Calamos Investment Trust N-CSRCertified annual shareholder report (management investment company)

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Family of Funds

ANNUAL REPORT OCTOBER 31, 2022

Alternative

Calamos Market Neutral Income Fund

Calamos Hedged Equity Fund

Calamos Phineus Long/Short Fund

Convertible

Calamos Convertible Fund

Calamos Global Convertible Fund

US Equity

Calamos Timpani Small Cap Growth Fund

Calamos Timpani SMID Growth Fund

Calamos Growth Fund

Calamos Growth and Income Fund

Calamos Dividend Growth Fund

Calamos Select Fund

Global Equity

Calamos International Growth Fund

Calamos Evolving World Growth Fund

Calamos Global Equity Fund

Calamos Global Opportunities Fund

Calamos International Small Cap Growth Fund

Sustainable Equities

Calamos Global Sustainable Equities Fund

Fixed Income

Calamos Total Return Bond Fund

Calamos High Income Opportunities Fund

Calamos Short-Term Bond Fund

Experience and Foresight

About Calamos Investments

For over 40 years, we have helped investors like you manage and build wealth to meet long-term objectives. Because investors have different time horizons, risk tolerances and goals, we offer funds to suit a variety of asset allocation needs. Our 20 mutual funds include equity, fixed income, convertible and alternative funds. We offer US funds as well as global and international choices.

We are dedicated to helping our clients build and protect wealth. We understand when you entrust us with your assets, you also entrust us with your achievements, goals and aspirations. We believe we best honor this trust by making investment decisions guided by integrity, discipline and our conscientious research.

We believe an active, risk-conscious approach is essential for wealth creation. In our early years, we pioneered the use of convertible securities as a means to control risk in volatile markets. We followed with strategies that combine convertibles and stocks, with the aim of participating in equity market upside with potentially less volatility than an all-stock portfolio. In 1990, we introduced our first stock fund, which invests in growth companies both large and small. Across our funds, our investment process seeks to manage risk at multiple levels and draws upon our experience investing through many market cycles. In a rapidly changing environment, we believe that this active management is essential.

We are global in our perspective. We believe globalization offers tremendous opportunities for countries and companies all over the world. In our US, global and international portfolios, we are seeking to capitalize on the potential growth of the global economy.

We believe there are opportunities in all markets. Our history traces back to the 1970s, a period of significant volatility and economic concerns. Since then, we have invested through the ebb and flow of multiple markets, each with its own set of challenges. Out of this experience comes our belief that the flipside of volatility is opportunity.

TABLE OF CONTENTS

Letter to Shareholders

JOHN P. CALAMOS, SR.

Founder, Chairman, and Global Chief Investment Officer

Dear Fellow Shareholder:

Welcome to your annual report for the 12 months ending October 31, 2022. In this report, you will find commentary from our portfolio management teams, a listing of portfolio holdings, financial statements and highlights, and detailed information about the performance and positioning of the Calamos Funds. Global markets have faced many challenges over the reporting period, and we understand investors have questions. Our teams have sought to address the key topics in the markets and how they have influenced the Funds, and it is our hope that you find this report informative.

When markets are volatile and economic conditions are uncertain, many investors find it difficult to stay invested. What I have learned during more than 50 years as an investor is that there are opportunities in all economic environments for active investors who follow disciplined processes. Especially during challenging markets, it's helpful to remember that market volatility and economic uncertainty are always part of the investment landscape—but short-term volatility sets the stage for long-term opportunities. For example, our teams seek to use short-term sell-offs to actively rebalance the Funds to gain exposure to investments with compelling long-term potential.

Market Review

During the 12-month reporting period, heightened investor anxiety buffeted global markets. Market participants worried about the Federal Reserve's interest rate increases, inflation, recessionary pressures, fiscal policy and geopolitical uncertainty. Although unemployment remained low in the US, well-publicized layoffs began to make their way into the headlines and corporate earnings expectations started to decline as companies confronted inflation and an array of unknowns related to regulations and taxes. Investors who were long accustomed to abnormally low interest rates faced a new reality: As the Fed dug into its tightening cycle and global central banks followed suit, the yield of the US 10-year Treasury crossed 4% for the first time since 2010. Although conditions began to stabilize as the reporting period closed—particularly for smaller-cap stocks—major equity, fixed-income and convertible market benchmarks closed the reporting period with losses.

Outlook

There are times when macro or geopolitical concerns—such as Fed policy, inflation or the war in Ukraine—drive most of the market's activity. This is the sort of the environment we find ourselves in today. We expect heightened volatility as markets seek clarity about whether a recession is indeed on the horizon or has perhaps

Letter to Shareholders

already begun. In the US, the fiscal policy backdrop remains uncertain, which is likely to contribute to volatility as market participants pay increasing attention to the 2024 election.

Investing through periods of rapid change is never easy, but it's important to maintain long-term perspective. For example, a 10-year Treasury yield above 4.0% feels ominous to many people today and is significantly higher on a percentage basis from its pandemic lows, but it's far less disconcerting relative to its long-term history. Similarly, the year-over-year inflation increases that are being reported are reflective of low starting points ("base effects"). We're also seeing indications that the worst may be behind us in terms of inflation.

That said, we remain highly attuned to potential risks—monetary policy errors and geopolitics are top of mind. Fiscal policy in the United States will be highly consequential for the markets and the economy. Business confidence is flagging, with real implications not only for corporate profits but also for individuals. Regulations that unduly disincentivize entrepreneurial activity create headwinds that may be felt by businesses first but eventually ripple over to households. Policies that encourage unchecked and excessive demand without a corresponding increase in supply ultimately come home to roost, including in the inflation we see today.

Here's another important point: Despite the big-picture challenges and uncertainties, over the long term, fundamentals win out. The Calamos Funds do not invest in the economy or the markets. Rather, our teams are focused on identifying individual securities that offer compelling risk-and-reward characteristics and on managing risk through a range of strategies. Our investment professionals are looking through the short-term noise to identify pockets of opportunity—including among innovative companies with quality fundamentals, those in thematic niches, and those that can demonstrate long-term resilience regardless of the macro backdrop. In a rising interest rate environment, price-to-earnings multiples can come down even if earnings are good, so our teams remain particularly mindful of valuations.

Thoughts on Asset Allocation

The "new normal" of the past decade was characterized by stable but low growth, low inflation and therefore, very low rates. In a zero-interest rate environment, the traditional 60% equity/40% fixed income asset allocation came up short, leading many investors to seek out the "bond surrogate trade" to create some yield. Now that interest rates have risen and are more likely to remain high, it makes sense to ask if we are returning to the "old normal"—built around owning stocks for capital appreciation and bonds for yield. Certainly, we see traditional fixed income as becoming more important in asset allocation. Because managing interest rate risk within fixed income allocations is paramount, we see especially attractive tailwinds for short-term bonds, the mainstay of Calamos Short-Term Bond Fund, as interest rates continue to adjust upward.

Asset allocation is always evolving, and today investors have new alternatives to consider for "old normal"-type problems. There are new approaches for investors to consider. For example, we believe the case for establishing or increasing allocations to liquid alternatives remains strong, to complement either traditional fixed income or equity allocations. (To learn more, see our fixed income alternative, Calamos Market Neutral Income Fund, and our equity alternatives, Calamos Phineus Long/Short Fund and Calamos Hedged Equity Fund).

Letter to Shareholders

Returning to traditional asset classes, we also see opportunities in the small- and mid-cap segment of the market. Many small-cap and mid-cap stocks provide a compelling blend of fundamental strength and valuations with healthy upside potential (for more, see our commentaries on Calamos Timpani Small Cap Growth Fund and Calamos Timpani SMID Growth Fund). Convertible securities, which are often issued by small cap and mid cap companies, offer another way to tap into this opportunity—with fixed-income characteristics providing the potential advantage of downside equity risk mitigation. Many of our funds utilize convertibles, including Calamos Growth and Income Fund (a multi-asset class fund) and Calamos Convertible Fund (a dedicated convertible offering).

Conclusion

As always, thank you for your trust. We are honored to serve you and help you achieve your asset allocation goals. I invite you to visit our website, www.calamos.com, for ongoing updates about the markets and thought leadership from our teams. We also provide information about asset allocation strategies for investors seeking income, capital appreciation, or both.

Sincerely,

John P. Calamos, Sr.
Founder, Chairman and Global Chief Investment Officer

Before investing, carefully consider a fund's investment objectives, risks, charges and expenses. Please see the prospectus containing this and other information or call 800-582-6959. Please read the prospectus carefully. Performance data represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

Diversification and asset allocation do not guarantee a profit or protection against a loss. Investments in alternative strategies may not be suitable for all investors.

*  Returns for the 12 months ended October 31, 2022: The S&P 500 Index, a measure of the US stock market, returned -14.61%. The MSCI All Country World Index, a measure of global stock market performance, returned -19.58%. The ICE BofA All US Convertibles Index, a measure of the US convertible securities market, returned -20.26%. The Refinitiv Global Convertible Bond Index, a measure of the global convertible bond market, returned -23.85%%. The Bloomberg US High Yield 2% Issuer Capped Index, a measure of the performance of high-yield corporate bonds with a maximum allocation of 2% to any one issuer, returned -11.76%. The Bloomberg US Aggregate Bond Index, a measure of the US investment-grade bond market, returned -15.68%.

Source: Calamos Advisors LLC.

Unmanaged index returns assume reinvestment of any and all distributions and, unlike fund returns, do not reflect fees, expenses or sales charges. Investors cannot invest directly in an index. Returns are in US dollar terms.

Investments in overseas markets pose special risks, including currency fluctuation and political risks. These risks are generally intensified for investments in emerging markets. Countries, regions, and sectors mentioned are presented to illustrate countries, regions, and sectors in which a fund may invest. There are certain risks involved with investing in convertible securities in addition to market risk, such as call risk, dividend risk, liquidity risk and default risk, which should be carefully considered prior to investing. Investments in alternative strategies may not be suitable for all investors.

Fund holdings are subject to change daily. The Funds are actively managed. The information contained herein is based on internal research derived from various sources and does not purport to be statements of all material facts relating to the securities mentioned. The information contained herein, while not guaranteed as to accuracy or completeness, has been obtained from sources we believe to be reliable.

Opinions are as of the publication date, subject to change and may not come to pass.

This information is being provided for informational purposes only and should not be considered investment advice or an offer to buy or sell any security in the portfolio.

Calamos Market Neutral Income Fund   (Unaudited)

OVERVIEW

The Fund combines two complementary strategies with different responses to volatility: arbitrage seeks alpha and uncorrelated returns, while hedged equity provides income from options writing and upside participation.

KEY FEATURES

^◼  Generates returns not dependent on interest rates, a key differentiator from traditional bond strategies.

^◼  Employs an absolute-return strategy with historically lower beta to fixed income and equity markets as well as lower volatility and limited drawdowns.

^◼  As one of the first alternative mutual funds, capitalizes on more than four decades of experience in the convertible space.

PORTFOLIO FIT

The Fund may provide potential diversification, particularly in a rising interest rate environment.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS MARKET NEUTRAL INCOME FUND

INVESTMENT TEAM DISCUSSION

Please discuss the Fund's strategy and role within an asset allocation.

Launched more than 30 years ago, Calamos Market Neutral Income Fund represents one of the first liquid alternative mutual funds and blends two main strategies—convertible arbitrage and hedged equity—with the aim of monetizing volatility. The Fund also uses opportunistic strategies to augment the main strategies: Special Purpose Acquisition Company ("SPAC") arbitrage offers a source of cheap optionality, and merger arbitrage offers a high probability of positive returns over a longer time horizon. Calamos Market Neutral Income Fund is designed to do the following:

^◼  Potentially enhance an investor's fixed-income allocation.

^◼  Actively pursue equity market upside while hedging downside risk.

^◼  Provide consistent absolute total return over varying market cycles.

In addition to seeking an attractive historical risk/reward profile, the Fund may enhance long-term portfolio diversification potential, a vital benefit given recent bouts of elevated equity volatility.

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Market Neutral Income Fund returned -5.01% (Class I Shares at net asset value), strongly outperforming the -16.04% loss for the Bloomberg US Government/Credit Bond Index while trailing the 0.85% return of the Bloomberg Short Treasury 1-3 Month Index.

What factors influenced performance during the annual period?

During the annual period, the equity and credit markets were challenged by global recession concerns, inflation, elevated oil prices, rising interest rates, and supply chain disruptions in the wake of the Covid-19 pandemic. Against this volatile backdrop, both stocks and bonds saw significant declines as represented by the S&P 500 Index (-14.61%) and Bloomberg US Government/Credit Bond Index (-16.04%).

During the period, the Federal Reserve (the Fed) raised its fed funds target rate from 0.00% – 0.25% to 3.00% – 3.25%. The Bloomberg US Aggregate Bond Index yield to maturity increased 334 basis points to 5.01%. In addition, according to Bloomberg, high yield corporate credit spreads widened 151 basis points to 483 basis points over US Treasuries. Rising interest rates and widening credit spreads impeded the bond component of convertibles during the annual period. At the same time, the rise in overnight interest rates improved the opportunity carry on cash received from short positions (our custodian rebates us overnight interest in excess of short borrowing costs).

During the annual period, the Fund's hedged equity strategy was held back by the S&P 500 Index market decline, given that the strategy's equity basket declined toward its put strike price. The elevated volatility provided attractive option-rebalancing opportunities, and the higher level of implied volatility in the options

Calamos Market Neutral Income Fund   (Unaudited)

market also benefitted the Fund. However, it was not enough to overcome the magnitude of the decline during the annual period. It is important to note that the options market gave rise to highly unusual conditions during the past year. Typically, in a large market sell-off, the implied volatility of put options would increase, causing an increase in the value of the option. However, during the annual period, the implied volatility of puts actually declined. As a result, the performance of the put hedge in the strategy underperformed expectations. This was not unique to the Fund and was evident in other option trading strategies too. For example, if an investor had tried to hedge their position in the S&P 500 Index using one-month, 5% out-of-the money puts, their hedged portfolio would still be down 20% year-to-date (as represented by the Cboe S&P 500 5% Put Protection Index).

The convertible arbitrage portion of the portfolio held up well and benefited from periods of volatility, which provided opportunities to profit from convertible hedge rebalancing. New convertible issuance cooled during the period, as the extreme volatility inhibited IPO activity across all asset classes. As of the year-to-date at the end of October, new global convertible issuance totaled $27.5 billion, far from the near record pace of issuance seen in 2020 and 2021.

The Fund's SPAC Arbitrage and Merger Arbitrage sleeves also held up well relative to the market declines.

How is the Fund positioned?

At the end of the annual period, the Fund had 49.7% in its hedged equity strategy and 50.3% in its arbitrage strategies. The arbitrage strategies included 38.1% in convertible arbitrage, 9.6% in SPAC arbitrage, and 2.6% in merger arbitrage.

Calamos Market Neutral Income Fund's hedged equity strategy declined slightly from 50.2% to 49.7% and finished the period with a delta hedge* on the higher side of our historical range. The strategy is positioned with a smaller call-write allocation along with a larger put purchase and the use of put spreads to enhance our hedge, which is above and beyond the outright long put allocation we always maintain in the Fund. However, the call-write allocation is smaller than our traditional trade. The current positioning provides for greater downside risk mitigation while also creating a favorable upside runway should the equity market rebound.

The allocation to convertible arbitrage was trimmed the most during the period (from 43.0% at the beginning of the period to 38.1%), and these assets were used to take advantage of attractive opportunities in the SPAC Arbitrage strategy, which provides a return and risk profile similar to convertible arbitrage.

The SPAC arbitrage sleeve increased from 5.6% to 9.6% during the annual period and reflected attractive opportunities to purchase SPACs below the value of the cash held in trust. These SPACs provided an attractive yield to expiration and a potential for upside should any of the SPAC sponsors announce an acquisition. We utilized SPAC arbitrage as a way to support the Fund's historically lower risk profile and steady returns; in essence, the strategy creates a cheap option with a risk-reward opportunity similar to convertible arbitrage. This said, the recent market environment has seen few SPACs issued and few merger announcements. Should the current SPAC environment persist, we expect the SPAC Arbitrage allocation may decline in favor of convertible arbitrage.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

A note concerning Morningstar Ratings for Calamos Market Neutral Income Fund Morningstar recently sought to refine its categorization of alternative funds, splitting large heterogeneous categories into smaller, more-focused peer sets. Calamos applauds Morningstar's continuous commitment to improving investor understanding of mutual fund offerings. As of April 30, 2021, Morningstar assigned the Fund to a new category, Relative Value Arbitrage, a group of only eight funds. With such a small set of data points, Morningstar has determined that funds in this category will not be assigned a star rating. The Fund's move to the Relative Value Arbitrage category has no bearing on the management of the fund itself, nor was it made in response to a change in the management of the Fund.

*  An options trading strategy that aims to reduce, or hedge, the risk associated with price movements in the underlying asset.

Calamos Market Neutral Income Fund   (Unaudited)

What are your closing thoughts for Fund shareholders?

The annual period was challenging across asset classes but provided a proof point for the Calamos Market Neutral Income Fund's diversification benefit within an asset allocation. The period brought turbulent volatility and rising interest rates, and the Fund was able to hold up significantly better than both the stock and bond markets.

Investors continue to be anxious about a myriad of headlines highlighting geopolitical strife, persistent supply chain disruptions, high oil prices, rising interest rates, and the effects of the US midterm elections. The Calamos Market Neutral Income Fund seeks to provide a stable positive return with a low standard deviation by monetizing the volatility of the markets.

If there is a silver lining behind the recent rise in interest rates, it is that higher rates have improved the performance outlook for the Fund. Those investors attracted to shorter-term bonds with their higher yields should also understand that the higher interest rates also support the Market Neutral Income Fund. In convertible arbitrage, the higher the overnight interest rate, the greater the carry on cash receives from the short sale of the convertibles' underlying stocks. In addition, new convertible issues are being brought to market with higher average coupons. The Fund's hedged equity sleeve may also benefit from an expected higher option premium capture. Finally, with SPAC Arbitrage, the SPACs cash in trust is also earning higher interest (after earning virtually no interest during the Fed's zero interest rate policy).

Calamos Market Neutral Income Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (5/10/00) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A, Class C and Class R6 shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Market Neutral Income Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.15%, Class C shares is 1.90%, Class I shares is 0.90% and Class R6 shares is 0.84%. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Load-adjusted returns are adjusted for the maximum front-end sales load of 2.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The Bloomberg US Government/Credit Index is comprised of long-term government and investment-grade corporate debt securities and is generally considered representative of the performance of the broad US bond market. The Bloomberg Short Treasury 1-3 Month Index is generally considered representative of the performance of short-term money market investments and is provided to show how the Fund's performance compares to public obligations of the US Treasury with maturities of 1-3 months.

The Cboe Volatility Index (VIX) is a leading measure of market expectations of near-term volatility conveyed by S&P 500 Index (SPX) option prices.

The Morningstar Market Neutral Category represents funds that attempt to eliminate the risks of the market by holding 50% of assets in long positions in stocks and 50% of assets in short positions.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Hedged Equity Fund   (Unaudited)

CALAMOS HEDGED EQUITY FUND

INVESTMENT TEAM DISCUSSION

The Fund's Strategic Approach and Role in a Portfolio

We believe the Calamos Hedged Equity Fund is an excellent portfolio diversifier. The Fund's investment approach seeks to be highly responsive to dynamic market conditions, blending a core long-equity portfolio with an actively managed options overlay. The Fund is often compared with more systematic or defined outcome product peers. Defined outcome products are designed to capture a certain amount of downside or upside each quarter, depending on where the market moves. However, there are disadvantages to not being nimble in these turbulent markets, such as having a capped upside that cannot offset successive losses on the downside.

Unlike our "mechanistic" peers, the Calamos tactical management approach seeks opportunities to generate alpha via option market dynamics and equity market volatility. The Fund seeks to take advantage of these opportunities by being favorably positioned for many outcomes.

How has the Fund performed?

The investment climate in 2022 is a far cry from what occurred during the 2008 collapse. While it is helpful to study the past, it is important to recognize that this investment climate is nothing like the Great Financial Crisis. In fact, it is the exact opposite. Markets will continue to deal with higher inflation, rising rates and volatility for some time to come, and it is our opinion that active risk management—seen as almost defunct from 2010 to 2020—is now imperative.

The Fund has been and will continue to seek to be well positioned to capture the equity market's upside with less risk than capped hedged equity funds and long-only equities. For the 12 months ended October 31, 2022 ("annual period"), Calamos Hedged Equity Fund was down -10.33% (Class I shares at net asset value) versus the S&P 500 Index -14.61% return and the Bloomberg US Aggregate Bond Index decrease of -15.68%. Since its inception on December 31, 2014, the Fund has gained 4.90% (Class I shares at net asset value) on an annualized basis versus 10.46% for the S&P 500 Index and 0.46% for the Bloomberg US Aggregate Bond Index.

The Fund maintained a beta of 0.52 for the annual period, which is in line with its historical beta of 0.50, versus the S&P 500 Index as of October 31, 2022. The Fund did a better job participating in the rally that occurred near the end of the annual period when the S&P 500 Index gained 8%. However, we still see this as a bear market rally similar to last summer's market action, and it is not unusual for these violent rallies to occur during bear markets. At the end of October, the S&P 500 Index was still deep in the red for the year-to-date period at -17.70%.

What factors influenced performance during the annual period?

The Federal Reserve (the Fed) continues to act aggressively to put a lid on inflation, which has pressured equity earnings and led to weaker economic performance. We expect that markets will continue to be challenged, though the recent oversold conditions in the equity markets have kept sellers at bay. The current volatility is far more settled than it was during the previous three quarters of 2022. The Cboe Volatility Index (VIX), known as the fear index, is trading around 22.5, still off the VIX mean of 19.5% but well under the Covid-19 mean of 23.5%. What would

OVERVIEW

The Fund blends a core long-equity portfolio with an actively managed option overlay. Tactical management creates opportunities to add alpha from option market dynamics and equity market volatility.

KEY FEATURES

^◼  Our investment approach is highly responsive to dynamic market conditions, unlike many less-active option-based strategies.

^◼  The investment team seeks to take advantage of opportunities the market presents, with a focus on being favorably positioned for as many outcomes as possible.

PORTFOLIO FIT

The Fund's options-based risk-management strategy can provide upside participation in equity markets while limiting downside exposure, thereby improving the quality of the ride.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Hedged Equity Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

be notable and needs monitoring is a challenge to a 35 VIX; if the market can break 35 and reach a 40 VIX, it may signal the end of the bear market. Until those levels are tested, we are still firmly in the grip of a bear market and subject to additional volatility.

How is the Fund positioned?

The Fund's active strategy management approach has generated equal or better results compared to long-only stocks or bonds. The options market's current landscape has allowed us to structure our hedge to emphasize better potential performance on the tails. This positioning provided additional mitigation over and above our average of 40% to 50% put notional minimum while also adding upside participation potential. The tradeoff was a reduction in the net income the Fund received from selling calls above our put cost. We felt this tradeoff was warranted and opportunistic given the Fund's defensive mandate, moderate volatility, and flattening skew* in the options market. Higher volatility (with the VIX at 27) and a flat option skew made our "North Star" baseline trade more appealing toward the end of the annual period. We use rallies to replace some of our put hedges with outright long puts, which appear attractive. At the end of the period, the Fund's net put representation was 79% with an average strike of 3596.

Our call positioning included a call write of -44%, gross short calls of -77%, and gross long calls of 33% as of October 31, 2022. In this case, gross long calls were in line with past positioning. At the end of the annual period and relative to the S&P 500 Index, our sector positioning was slightly overweight in the consumer discretionary and information technology sectors. The portfolio was slightly underweight in the materials, financials, and real estate sectors. Relative to the S&P 500 Index, the Fund's market-cap positioning maintained a heavier relative weight to larger capitalization (>$25 billion) holdings and a lighter weight to small- and mid-capitalization ($1 to $25 billion) holdings.

What closing thoughts do you have for Fund shareholders?

If the VIX increases to 40 and the S&P 500 Index holds above the October low of 3491, we believe equities can achieve higher-than-average returns in the following months based on historical precedence. As in June when the S&P 500 Index was challenging market lows before rallying, the period-end market of 2022 presents a similar setup with the Index back up at 3860. The opportunity cost of exiting the market outweighs the cost of additional short-term pain. At this point in the S&P 500 Index, we are taking a more constructive long-term view. Strategically, one of the key near-term drivers moving forward will be liquidity. There is no Fed put holding up the market, and because we do not have that central bank backstop, it is doubtful that the equity market recovery will look like a "V." Subsequently, there will probably be much backing and filling short-term. Time will tell whether the shift in implied volatility represents investors' overshooting because of inflation and rising rates. Presently, growth momentum remains strong in the United States. We expect earnings, Fed tapering, rate hikes, inflation, and war to continue spurring a spike in volatility, which is not unexpected or unprecedented. Some of the volatility spikes seem to be synchronized with the

*  Skew describes asymmetry from the normal distribution as a statistical data set. Option skew is the difference in implied volatility between out-of-the-money options, at-the-money options, and in-the-money options. Volatility skew, which is affected by sentiment and the supply-and-demand relationship, provides information that helps fund managers determine whether to write calls or puts. The Cboe SKEW Index ("SKEW") is an index derived from the price of S&P 500 tail risk. Similar to the VIX®, the S&P 500 tail risk price is calculated from the S&P 500 out-of-the-money options prices.

Calamos Hedged Equity Fund   (Unaudited)

GROWTH OF $1,000,000: SINCE INCEPTION (12/31/14) THROUGH 10/31/22

Fed tapering asset purchases and can be characterized as overreactions whereas other spikes usher in phases of above-average volatility. In our opinion the Fund is poised to participate in any upside while providing an enhanced income stream from well-positioned call spreads and our tracking portfolio's equity dividends. Should markets retreat, the dividend income stream, the put spreads, and outright long puts used in the Fund may mitigate any potential downside.

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.18%, Class C shares is 1.93% and Class I shares is 0.93%.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown includes the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum frontend sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

The Bloomberg US Aggregate Bond Index is considered generally representative of the investment-grade bond market.

The Cboe Volatility Index (VIX) is a leading measure of market expectations of near-term volatility conveyed by S&P 500 Index (SPX) option prices.

The Cboe SKEW Index essentially tracks the willingness of investors to pay up for downside protection on the S&P 500 Index.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Phineus Long/Short Fund   (Unaudited)

OVERVIEW

The Fund seeks strong risk-adjusted and absolute returns across the global equity universe. The Fund uses a global long/short strategy to invest in publicly listed equity securities.

KEY FEATURES

^◼  Fundamental global approach blends top-down and bottom-up considerations.

^◼  Flexible asset allocation allows for all investment styles, market caps and geographic regions depending on the market environment.

^◼  Comprehensive approach assesses stock, industry, style, country and market factors.

^◼  Knowledge-based industry concentration includes technology, communications, media, financials and health care.

PORTFOLIO FIT

The Fund seeks to provide strong risk-adjusted returns via an alternative solution that complements and diversifies a global or US equity allocation.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS PHINEUS LONG/SHORT FUND

INVESTMENT TEAM DISCUSSION

What is the essence of the investment approach?

Through a global long/short structure, Calamos Phineus Long/Short Fund invests in publicly listed equity securities. Components of that strategy include the following:

^◼  A fundamental global approach that blends top-down and bottom-up considerations. Company analysis is integrated with industry, thematic and macro research.

^◼  An inclusive framework for identifying potential returns and associated risks. The framework accounts for company, industry, style, country and market factors.

^◼  Flexible capital allocation allowing for all investment styles, market caps and geographic regions. The investment universe is global, liquid and scalable. Exposure levels and investment styles depend upon market conditions and the economic cycle.

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Phineus Long/Short Fund returned -5.25% (Class I shares at net asset value), outperforming the S&P 500 Index -14.61% return and the MSCI World Index -18.09% return over the same period.

Since its inception on May 1, 2002, the Fund has returned 9.93% on an annualized basis (Class I shares at net asset value), which markedly outperformed both the S&P 500 Index and MSCI World Index returns of 8.56% and 7.42%, respectively, since the inception period.

What factors influenced performance during the annual period?

The Fund's outperformance relative to the global indices largely reflected the Fund's underweight exposure to the equity derivatives of long duration and positive returns on general market hedges. The Fund concluded the period with an average net equity delta-adjusted exposure of 59.89%, which compares to its average net equity exposure of approximately 28% (on a cash basis)^† since inception in 2002.

The annual period was extraordinary by most standards. It was marked by a European war, supply chain challenges, the lowest labor participation rate in decades, and over $5 trillion in federal fiscal stimulus spending, all of which contributed to an annual CPI in September of 8.25% that was highlighted by a year-over-year increase in gasoline prices of 18.2%. This situation prompted the Federal Reserve (the Fed) to increase short-term rates six times through early November 2022, bringing the target rate to 3.75% – 4.00%, while consequently fueling speculation that more rate hikes were likely in 2023. All of these events

†  When the portfolio management team evaluates the Fund's exposures and related risks, it includes calculations based on a delta-adjusted basis that measures the price sensitivity of an option or portfolio to changes in the price of an underlying security. Delta-adjusted basis exposure is calculated by Calamos Advisors LLC and is specific only to that point in time since a security's delta changes continuously with market activity. The investment team began calculating the Fund's exposure on a delta-adjusted basis in August 2008.

Calamos Phineus Long/Short Fund   (Unaudited)

have contributed to a broad and deep sell-off of financial assets during the period as market volatility, at times stoked by varied interpretations of Fed messaging, has been rampant.

Most investors agree that the path of inflation will dictate the direction of financial markets in 2023. Disinflation will almost certainly lead to higher equity and bond prices as well as improved prospects for the US economy.

Two arguments support this view. The first is history itself, which highlights that an inflection in the inflation cycle is commonly coincident with the direction of equity prices. The second is monetary policy under the Federal Reserve. Today, investors fear the Federal Reserve because they know the Fed fears inflation.

The gap between projected versus actual monetary policy in 2022 has created considerable dissonance. Through the post-2008 era, the Fed offered considerable transparency to markets. For the past three quarters, policy visibility has become obscure in the extreme. Market volatility reflects this uncertainty as much as the absolute level of interest rates.

Fund performance amid all of these developments was respectable in both absolute and relative terms. First, we have been wary of the equity derivatives of long duration for much of the past year. In December 2021 we further distanced the portfolio from long-duration growth and defensive areas.

We then added additional index hedges in early 2022 that cushioned the Fund from the initial stages of the market retreat with the result that both the long and short books have been additive to performance over the period. The reorientation of the Federal Reserve that effectively ended the "Fed put" became apparent with the release of the December FOMC minutes, which signaled that we should no longer lean aggressively into equity risk.

What helped and hurt performance over the annual period?

Early in the period we focused on cyclicals that we believed were poised to outperform, given the post-pandemic pent-up demand in airlines, hotels, gaming, transportation, and defensive stocks. Although many of these areas proved to be accretive, several long holdings in consumer discretionary did not meet expectations. Although we had little exposure at the end of the period, we did capture profits in energy earlier in the year. Given the market volatility and the overall equity market declines, our hedges on US equity markets have been helpful to us over the course of the year.

The Fund's long position in energy and materials, as well as both long and short positions on market indexes, were the largest contributors. Conversely, long positions in information technology, industrials, and communication service companies hindered performance. Notable contributors during the period included a short position on the S&P 500 ETF Trust -35.22% average of net exposure over the period (hedge), long positions on Snowflake 0.43% average over the period (information technology) and Itaú Unibanco 1.90% average over the period (financials). Notable detractors during the period included long positions on Caesars Entertainment Inc. 2.06% as of period end (consumer discretionary), Twilio Inc. 1.38% average over the period (information technology) and The Boeing Company 1.65% average over the period (industrials).

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Phineus Long/Short Fund   (Unaudited)

How is the Fund positioned in the context of the global economic cycle?

Net equity exposure (delta-adjusted) concluded the annual period at 59.9% versus 57.2% at the start of the period. This compares with the average net equity exposure of approximately 28% (cash basis) since inception in 2002. The Fund leaned modestly into equity risk throughout the period as markets became unsettled by higher interest rates, rapid inflation, Fed policy mixed signals, the continuing war in Ukraine, energy concerns in Europe, and increasing economic challenges in China due to its "zero tolerance" Covid-19 policy.

Our continuing conviction has been our cautious view on duration and its equity derivatives. This translates into the continued bias toward shorter duration, more profitable businesses versus those with less support from earnings, cash flow and tangible assets or book value. We have been wary of stocks where the bulk of their value depends on assumptions about growth in the far future. This positioning sheltered the Fund from some of the most egregious stock disappointments of the period as markets struggled to price these assets in an increasingly inflationary environment. The Fund continued to favor names perceived as more cyclical with recovery potential during the year. The broadest exposures for the long book are industrials and transports, followed by financials. The Fund currently maintains, and had maintained throughout the period, a US bias.

Early in July the Fund selectively reengaged opportunities that we view as QGARP, or quality growth at a reasonable price. This appeared to be the right move as the market recovered in the first part of the third calendar quarter off June lows.

Many of our cyclical themes have anticipated the shift from goods to services as the world slowly emerges from the pandemic. This implies a sustained recovery in travel and entertainment along with a return to the office. In contrast, producers and retailers of goods will struggle with less volume and less pricing power into 2023 as the "stay at home" bubble pulled forward years of demand. Investors are in the process of recognizing this thematic shift, and we might worry it has become consensus positioning were it not overshadowed by recession fears.

Technology stocks have been materially derated. The list of companies that have announced workforce reductions or lowered outlooks grows daily, though material resets have been largely focused on semiconductors and PC-related names. With few exceptions, software and internet names have yet to revise outlooks, apart from currency impacts. Until forward estimates come down broadly and the stocks stabilize in response, we are reluctant to engage names that are not supported by quality earnings and cash flow.

After profit taking, energy was moved to an underweight in Q2 2022, though the Fund maintains a small position. Although oil fundamentals are underpinned by years of supply underinvestment, prices continued to decline from March and June peaks as Chinese economic disruption and lower seasonal demand reduced near-term fears of shortages. Despite the war in Ukraine conflict, it looks as though Europeans have a great deal more capacity to manage their situation than earlier feared.

Financials are a conflicted group. Revenue and earnings are benefiting from high growth rates of net interest income, yet this is generating macro fears of a harder economic landing. Consumer credit has been resilient, and we favor regional banks over their larger money center peers.

Calamos Phineus Long/Short Fund   (Unaudited)

In industrials our focus is on aerospace, airlines and select defense names. An eventual reopening in China and travel recovery in the broader Asia Pacific region are other catalysts that will draw attention in late 2023.

We are optimistic that the demand and pricing outlook for airfares is constructive because of the changing capacity outlook. Higher oil prices, higher financing costs, pilot shortages and equipment delays are making it difficult for the lowest cost players in the market to add undisciplined flights. The recovery in corporate and international travel has gained steam, which bodes well for the higher quality carriers with lower leverage ratios.

The Fund is underweight in the non-US economies. Within its US holdings, the Fund maintains a bias toward those with a higher percentage of domestic revenue. Europe will be challenged by energy concerns heading into the winter. Finally, and after years of denial, investors are turning downbeat on Chinese growth prospects and equity market performance—and with good reason. The catalyst for improved China sentiment requires changes to the zero-Covid -19 policy, but China has painted itself into a corner. Beijing would need to go overboard with stimulative policy to shift the grave winds blowing over the Chinese economy, but such a policy shift is unlikely.

What is your macro perspective heading into 2023?

The monetary setting is troubling, yet fundamentals are resilient. The enemy of equities is not inflation but deflation in output and profits, which we believe is unlikely until late 2023 at the earliest.

Policy uncertainty argues for diversification across the long portfolio, which is balanced between select quality GARP¹ opportunities and cyclicals that have become "too cheap" on recession fears.

Markets are dealing with multiple headwinds to economic growth rather than the momentous conditions for a severe financial recession. As inflation risks ebb, tail risks will diminish accordingly.

Today's negative sentiment is infectious, driving broad de-risking by investors. Yet we believe the medium-term outlook for equities is improving, and the Fed will "pause to assess the outlook" before year-end.

Turning points in inflation are veiled in uncertainty. This is especially true in a post-Covid -19 era that has bifurcated the winning and losing industries across an economy that is still absorbing the footprint of the pandemic. Some sectors of the economy have begun to disinflate rapidly, whereas others are still struggling to normalize supply.

We are firmly in the disinflation camp. It is our opinion that the inflation surge of the past five quarters will reverse symmetrically over the next four to five quarters. Pricing pressures are easing broadly—in some places modestly—but in others decisively.

If we do not see further incremental policy tightness by the Fed, the bad news on policy is almost certainly priced into markets. Traditional analysis implies we should not see the consequences of this tighter policy on the economy until much later in 2023. This creates a window of opportunity for investors that opened at some point in October 2022 and, possibly, extends into spring of 2023.

Calamos Phineus Long/Short Fund   (Unaudited)

Today, investors are positioned for heightened volatility as everyone awaits more clarity on policy. At the same time, the medium-term outlook for equities appears more favorable. Corporate profitability remains resilient, and valuation excesses have been wrung out of most stocks. Investor sentiment is at negative extremes, underscoring that many of today's concerns are already "in the price."

Although the risks of recession have heightened, we believe an actual downturn is neither imminent nor likely to be severe. Whether one looks at the yield curve (3-month to 10-year yields), growth in money aggregates, the housing cycle, or corporate margins, the message is the same. Material demand risk may not appear until much later in 2023.

And when recession does appear, there is a good chance it will be mild. First, the balance sheets of households and the corporate sector remain strikingly healthy based on key metrics like debt-to-income ratios and liquidity levels. The seeds of the end of any expansion are normally behaviors that lead to excessive spending and borrowing, which has not happened in the current cycle.

Another reason for optimism is that many recessions have been exacerbated by a banking crisis, which is another way of saying that private sector balance sheets came under stress. Yet the current US banking industry is squeaky clean. Finally, the footprint of the pandemic implies that any downturn in demand could feel relatively mild because the supply side of the economy is still catching up with demand.

Although the economy faces headwinds in key sectors like housing, the nuanced query may be what kind of slowdown will it be, as opposed to the binary question of whether a recession will come or not. And here, the nature of risks to housing, consumers and corporate balance sheets as well as the role of inflation versus deflation become paramount.

Today's problem is inflation not deflation, which is a radically different setting for incomes and balance sheets across the private sector. This reality implies that it would be nearly impossible to have the kind of deleterious collapse in the economy that occurred in late 2008.

What are your closing thoughts for Fund shareholders?

We expect equities to find key support in the coming weeks. Before the infamous "Fed put" became embedded in investor psychology, equity bottoms were a process that typically included double bottoms or a retest of important lows, just as the June low is now being tested. Today's pattern is consistent with a gradual stabilization of equity values into year-end.

This constructive setting at the margin assumes no incremental policy tightness by the Federal Reserve and, thus, the bad news on the policy side is priced into markets. This is consistent with a stabilization in equity values. The skew of risk will be more to the upside if the mix of inflation and employment data can highlight a gradual post-pandemic normalization in the structure of economic growth.

We are balancing heightened uncertainty in the short-term—reflected in investor pessimism and broad de-risking—with improving medium-term prospects for equities. For the portfolio, this has implied more tactical positioning shifts and the execution of option strategies that can mitigate further downside without limiting the upside opportunity.

Calamos Phineus Long/Short Fund   (Unaudited)

What is not embedded in today's markets is the possibility that the Fed manages to thread this narrow needle of policy normalization, leading to moderating economic growth, stable interest rates, and sustained corporate profits as nominal measures of economic activity remain comfortably positive. This is the story for 2023 if a window of disinflation emerges.

Looking beyond this, the long bull market in financial prices ended in December 2021. We believe the major indices will move in a broad range-bound pattern between today's levels and the former highs for much of the current decade. This amounts to a reconstitution of the investment landscape as the long era of price stability is replaced by a new experience of quasi price instability.

We are committed to the view that equities will bottom through late autumn with the setting becoming more constructive as disinflation takes hold in 2023.

ANNUALIZED RETURN: SINCE INCEPTION (5/1/02) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

The performance shown for periods prior to April 6, 2016 is the performance of a predecessor investment vehicle (the "Predecessor Fund"). The Predecessor Fund was reorganized into the Fund on April 6, 2016, the date upon which the Fund commenced operations. On October 1, 2015, the parent company of Calamos Advisors, purchased Phineus Partners LP, the prior investment adviser to the Predecessor Fund ("Phineus"), and Calamos Advisors served as the Predecessor Fund's investment adviser between October 1, 2015 until it was reorganized into the Fund. Phineus and Calamos Advisors managed the Predecessor Fund using investment policies, objectives, guidelines and restrictions that were in all material respects equivalent to those of the Fund. Phineus and Calamos Advisors managed the Predecessor Fund in this manner either directly or indirectly by investing all of the Predecessor Fund's assets in a master fund structure. The Predecessor Fund performance information has been adjusted to reflect Class A, Class C and Class I shares, expenses. However, the Predecessor Fund was not a registered mutual fund and thus was not subject to the same investment and tax restrictions as the Fund. If it had been, the Predecessor Fund's performance may have been lower.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Phineus Long/Short Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 2.36%, Class C shares is 3.11% and Class I shares is 2.11%. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares. Returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graph does not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

The MSCI World Index (US Dollars) is a market-capitalization weighted index composed of companies representative of the market structure of developed market countries in North America, Europe and the Asia/Pacific region.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Convertible Fund   (Unaudited)

CALAMOS CONVERTIBLE FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

The convertible and equity markets were challenged during the 12 months ("annual period") that ended October 31, 2022, by recession concerns, inflation, elevated oil prices, rising interest rates and supply chain disruptions from the Covid-19 pandemic. Against this volatile backdrop, the US convertible market, represented by the ICE BofA All US Convertibles Index (VXA0), declined -20.26% and lagged behind the S&P 500 Index return of -14.61%. Calamos Convertible Fund returned -22.09% (Class I shares at net asset value), moderately trailing the convertible index.

Since the Class I shares inception on June 25, 1997, the Fund has returned 7.80% on an annualized basis in line with an annualized gain of 7.96% for the ICE BofA All US Convertibles Index (VXA0) and a 7.98% annualized return for the S&P 500 Index.

What factors influenced performance during the annual period?

The convertible market is well represented by small and mid-sized growth issuers. The annual period was especially challenging for these issuers as evidenced by the -27.38% decline of the Russell 2500 Growth Index. Given that the underlying stocks of the convertible market declined -34.50%, convertibles provided downside risk mitigation by participating in only 58% of the decline of their underlying stocks. The equity market decline also meant that convertibles moved closer to their bond floor.

From an economic sector perspective, the Calamos Convertible Fund benefited from its underweight allocation in the real estate sector and its favorable selection in the information technology and materials sectors. In information technology, the Fund benefited from its relatively overweight position within the strong-performing semiconductor equipment industry. In addition, selection in the semiconductor equipment, semiconductors, and data processing & outsourced services industries held up better than index peers. In materials, the Fund benefited from strong security selection in the steel industry. Conversely, selection in the health care sector, an underweight allocation and selection in utilities, and an overweight allocation in the consumer discretionary sector detracted from results. The Fund's holdings in biotechnology, life sciences tools and services, and healthcare technology lagged within health care. In the utilities sector, selection in the electric utilities industry was a drag on performance.

How is the Fund positioned?

During this environment of uncertainty and volatility, we remain focused on managing the risk/reward trade-offs within a portfolio. Convertibles are hybrid securities that can act like equities or bonds, depending on movements in the markets. Although the asset class is diversified across market caps and sectors, small and mid-cap companies are well represented, as we mentioned earlier. Equity valuations have declined markedly among small and mid caps, including many companies that issued convertibles to fund their growth initiatives. To take advantage of the reset in the equity markets, we have maintained our emphasis on balanced convertibles with favorable asymmetric risk/reward profiles. Because this segment offers a healthy blend of equity and fixed income characteristics,

OVERVIEW

The Fund invests primarily in convertible securities of US companies that are diversified across market sectors and credit quality.

KEY FEATURES

^◼  Leverages more than four decades of research and experience in convertible security investing.

^◼  Provides diversification across market sectors and credit quality, emphasizing midsize companies with higher-quality balance sheets.

^◼  Seeks to provide upside participation in equity markets with less exposure to downside than an equity-only portfolio over a full market cycle.

^◼  Takes environmental, social and governance (ESG) factors into account, evaluating whether they impact a company's cash flow, risk profile and long-term returns.

PORTFOLIO FIT

When used in conjunction with an equity allocation, the Fund offers a potential way to manage risk by employing securities that engage in upside equity movements with limited downside participation.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Convertible Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

balanced convertibles can provide upside equity participation while potentially dampening downside volatility.

Additionally, as credit spreads have widened across fixed income markets, we have selectively invested in convertibles with more pronounced fixed income attributes ("busted convertibles") that we believe can benefit from spread improvement and provide a positive yield to maturity. However, consistent with our focus on risk management, we seek to avoid the most distressed portion of the busted convertible market.

Growth sectors such as technology, health care and consumer discretionary remain the largest allocations in the portfolio. We favor companies that are executing well despite macro uncertainties and can potentially benefit from increased demand for products and services that enhance productivity to offset rising corporate costs. We are also emphasizing companies positioned to benefit from longer-term secular themes such as energy efficiency and cybersecurity. Financials are the largest relative underweight in the Fund. Convertible structures in the sector tend to have unfavorable risk/reward characteristics, and many issuers are susceptible to the negative impact of higher interest rates.

What closing thoughts do you have for Fund shareholders?

Persistent inflationary pressures and monetary policy tightening are expected to contribute to high levels of uncertainty across the financial markets. This heightened volatility is likely to persist until there is greater clarity on the path of these risks, but we believe that short-term volatility can create longer-term opportunity and that the Calamos Convertible Fund is well positioned to participate in a market rebound while offering downside risk mitigation should the market look to retest recent lows.

To say that the equity and credit markets have experienced turbulence because of rising inflation and interest rates as well as intense geopolitical risks is stating the obvious. Convertibles have not been immune to this increase in volatility, which has also contributed to the subdued pace of new convertible issuance. While we anticipated a deceleration in the annual volume of new convertibles after back-to-back years of near-record amounts, issuance during the annual period was impacted by heightened global uncertainty fomented by multiple factors. Issuance accelerated toward the latter part of the annual period, and we expect the pace of new issuance to achieve a brisk clip once macro uncertainty subsides. Typically, after periods of volatility-induced slowdowns in new capital market issuance, the convertible market tends to be one of the first to reopen, and the initial deals tend to be attractively priced. We also anticipate—and would welcome—higher cash coupons given the overall rise in interest rates across markets. Despite the issuance slowdown, the strong issuance from 2020 and 2021 expanded the market and pushed back the maturity wall in the existing convertible market, which provides attractive opportunities in our view.

While this is a short window, we have been encouraged by the positive convexity convertibles have shown late in the annual period. Having participated in the July through mid-August rally, convertibles also held up better relative to other risk assets during the late August through September decline.

Calamos Convertible Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (6/25/97) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Convertible Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.08%, Class C shares is 1.83% and Class I shares is 0.83%. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Load-adjusted returns are adjusted for the maximum front-end sales load of 2.25% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income of taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The ICE BofA All US Convertibles Index is comprised of approximately 700 issues of only convertible bonds and preferreds of all qualities. Since inception data for the index is shown from 6/30/97, since data is only available for full monthly periods.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

Due to their structural complexities, the attributes of convertibles may vary. Therefore, they are typically categorized as Yield Alternatives represented by the US CV Index (VYLD), Total Return Alternatives represented by the US CV Index (VTOT), or Equity Alternatives represented by the US CV Index (VEQU).

The ICE BofA Total Return US Convertibles Index is a subset of ICE BofA All US Convertibles Index including securities with a delta greater than or equal to 0.4 and less than 0.8 (VTOT).

The ICE BofA Yield Alternative US Convertibles Index (VYLD) is a subset of ICE BofA All US Convertibles Index including securities with a delta less than 0.4 (exhibiting bond-like characteristics).

The ICE BofA Equity Alternative US Convertibles Index (VEQU) is a subset of ICE BofA All US Convertibles Index including securities with a delta of 0.8 and greater (exhibiting stock-like characteristics).

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Global Convertible Fund   (Unaudited)

CALAMOS GLOBAL CONVERTIBLE FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

The convertible and equity markets were challenged during the 12 months ("annual period") ended October 31, 2022, by recession concerns, inflation, elevated oil prices, rising interest rates and supply chain disruptions from the Covid-19 pandemic. Against this volatile backdrop, the global convertible market, represented by the Refinitiv Global Convertible Bond Index, declined -23.85% and lagged behind global equities in developed markets as represented by the MSCI World Index's -18.09% return. Calamos Global Convertible Fund returned -25.82% (Class I shares at net asset value), moderately underperforming the convertible benchmark index.

What factors influenced performance during the annual period?

Small- and mid-cap growth issuers are well represented in the global convertible market, and the annual period proved to be especially challenging for convertibles issued by these smaller companies. The underlying stocks of the Refinitiv Global Convertible Bond Index were down -38.72% on average, significantly underperforming the broader equity market. Although convertibles underperformed the MSCI World Index, they demonstrated their resilience on the downside by participating in only 62% of their underlying stocks' decline. As the equity market moved lower, convertibles moved closer to their bond floor, further improving their downside resilience. At the end of the annual period, more than half of the global convertible market was priced below par.

During the period, the Federal Reserve (the Fed) raised its fed funds target rate from 0.00% – 0.25% to 3.00% – 3.25%. The Bloomberg Global Aggregate Bond Index yield to maturity also increased 252 basis points to 3.82%. In addition, global high yield corporate credit spreads widened 180 basis points to 559 basis points, according to Bloomberg. Rising interest rates and widening credit spreads impeded the bond component of convertibles during the annual period.

From an economic sector attribution perspective, the Calamos Global Convertible Fund benefited from security selection in the consumer discretionary sector, where holdings in the internet & direct marketing retail and hotels, resorts & cruise lines industries held up better than index names. Favorable security selection in the communication services sector also added value. Specifically, the portfolio benefited from a relatively heavy position in the strong-performing wireless telecommunication services sector in addition to a strong selection in the cable & satellite industry. The sectors that most detracted from performance were health care and information technology. Within health care, an underweight allocation and security selection in the biotechnology industry held back the relative return as did holdings within the health care equipment industry. In information technology, the relative return was hindered by security selection within the application software, semiconductor equipment, and systems software industries.

From a geographic perspective, the Fund benefitted from favorable selection in Emerging Latin America and Emerging Europe & South Africa. Security selection within Europe, the United States and Japan held back the relative result.

How is the Fund positioned?

We remain focused on maintaining an attractive risk/reward profile in the Fund. Convertible securities vary in their levels of equity and fixed income sensitivity, and

OVERVIEW

The Fund invests in global convertible securities, striving to balance risk/reward while providing growth and income.

KEY FEATURES

^◼  Provides broadly diversified exposure to the global convertible bond universe.

^◼  Leverages more than 40 years of research in convertible security investing.

^◼  Seeks to provide upside participation in equity markets with less exposure to downside than an equity-only portfolio over a full market cycle.

^◼  Blends global investment themes and fundamental research via active management.

^◼  Takes environmental, social and governance (ESG) factors into account, evaluating whether they impact a company's cash flow, risk profile and long-term returns.

PORTFOLIO FIT

Consisting of convertible securities that can participate in upside equity movements with potentially limited downside exposure, the Fund can provide a means to manage risk in conjunction with an equity allocation. The Fund can also serve a role within a fixed-income allocation, as convertibles have performed well during periods of rising interest rates and inflation.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Global Convertible Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

we adjust the Fund's overall exposures on an ongoing basis. During the annual period, the delta or equity sensitivity of convertibles declined as convertibles retreated closer to their bond floors when their underlying equities dropped in value. Although we added equity exposure through investments in new issues, this was offset by the decline in the delta. As a result, the Fund's overall level of equity sensitivity declined during the annual period and is currently in line with the global convertible market as measured by the Refinitiv Global Convertible Bond Index.

Despite the slowdown in issuance and the challenging market environment, we have found opportunities to put cash to work and rebalance the portfolio in response to evolving market conditions. This includes investing in convertibles with balanced risk/reward attributes as well as select convertibles trading near their bond floor ("busted convertibles") that offer favorable yield-to-maturity characteristics.

From a sector standpoint, the Fund's largest sector weightings include information technology, consumer discretionary and health care. The lightest allocations reside in the consumer staples, energy and materials sectors. Relative to the Refinitiv Global Convertible Bond Index benchmark, information technology, consumer discretionary and health care represent the largest overweights, whereas the industrials, communication services and materials sectors make up the most significant relative underweight allocations.

From a regional perspective, the United States and Europe constitute the largest allocations, and Emerging Europe & South Africa and Canada represent the lightest allocations. The Fund is underweight in Europe, reflecting both the paucity of bottom-up opportunities and the concerning macro environment.

What closing thoughts do you have for Fund shareholders?

The global outlook is murky given rising interest rates in the United States. The Federal Reserve is determined to break the back of inflation; although this should be good news in the long run, we worry that the Fed may break something else in the process—perhaps the most over-leveraged parts of the UK pension industry that the Bank of England essentially bailed out recently. The US labor market has remained surprisingly resilient, but conditions point to a recession on the horizon. In Europe, the outlook is bleaker, given the continued war waged by Russia on Ukraine. The strength of the US dollar is also not making it any easier for Europe to get through its energy crisis.

After two years of near-record issuance, global convertible issuance, and IPO activity in other asset classes, has been slow in 2022. This slowdown in convertible issuance normally occurs during periods of equity market volatility. For example, after Lehman Brothers went under in 2008, we did not see a new convertible issued until March 2009. Although we do not expect that long a lull in issuance and we saw issuance begin to pick up late in the annual period, it may be a bit longer before the taps fully reopen. When they do, we expect to see a deluge of paper. Usually when equity capital markets are closed, convertibles are the first to reopen, and the early deals are often attractively priced.

We believe that convertibles provide an attractive way for investors to take some risk off the table while staying invested in the equity market. The recent pullback in the underlying stocks of convertible issuers has resulted in overall equity sensitivity toward the lower end of the post-Covid-era range. Convertibles have also moved closer to their bond values, as evidenced by the fact that more than half of the convertible market traded below par at the end of the annual period.

Calamos Global Convertible Fund   (Unaudited)

Although we view convertibles to be strategic allocations that should be held over full market, economic and interest rate cycles, the pullback and volatility in the market fomented by rising rates may provide tactical opportunities in addition to strategic ones. For many investors, it's tough to buy equities when volatility is occurring, and convertibles are a way to have equity exposure with less equity market sensitivity.

GROWTH OF $1,000,000: SINCE INCEPTION (12/31/14) THROUGH 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.25%, Class C shares is 2.00% and Class I shares is 1.00%. The Fund's Investment Adviser has contractually agreed to reimburse Fund expenses through 3/1/23 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses and extraordinary expenses, if any) of Class A, Class C and Class I shares are limited to 1.35%, 2.10%, 1.10% of average net assets, respectively. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown includes the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 2.25% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The Refinitiv Global Convertible Bond Index (USD) is designed to represent the global convertible market.

Unmanaged index returns assume reinvestment of any and all distributions and, unlike fund returns, do not reflect fees, expenses or sales charges. Investors cannot invest directly in an index.

Calamos Timpani Small Cap Growth Fund   (Unaudited)

OVERVIEW

The Fund invests in the equity securities of small-capitalization companies with high, sustainable growth potential, which may exceed market expectations.

KEY FEATURES

^◼  Combines fundamental research with the analysis of market estimates to identify the underestimated growth differential between a company's business strength and market expectations of that strength.

^◼  Pursues active management in a less-followed investment space.

^◼  Analyzes secular trends to uncover exploitable investment opportunities specific to small-cap companies.

PORTFOLIO FIT

Investing in small-cap companies is an important component of a diversified investment strategy. Smaller companies tend to experience greater growth and outperform larger companies.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS TIMPANI SMALL CAP
GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Timpani Small Cap Growth Fund posted a return of -37.57% (Class I Shares at net asset value), underperforming the -26.02% loss of the Russell 2000 Growth Index.

Since Class I shares inception on March 23, 2011, the Fund has returned 10.67% on an annualized basis, while the Russell 2000 Growth Index returned 8.53% over the same period. We believe these comparisons demonstrate the Fund's ability to outdistance its benchmark over full market cycles.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take to tame inflation. Before the start of this annual period, the Fed increased its inflation forecasts, in turn raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer duration equities (businesses whose value significantly depends on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and, by the end of the annual period, had raised rates five times for a total of 300 basis points, while pointing to additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, though the decline has been interrupted by several strong rallies, which offered hope the worst economic fears may have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally, in advance of a significant and contentious midterm election in the United States. Adding to investors' woes over the annual period, the bond market delivered difficult performance as evidenced by the Bloomberg US Aggregate Bond Index's -15.68% return.

Small-cap stocks started their decline in November, which was a bit earlier than the broad market as represented by the S&P 500 Index. Macro concerns dominated investor sentiment as many small company stocks, especially growth stocks, saw share prices decline despite favorable earnings reports and positive company guidance. Companies that had exhibited strong growth and stock performance previously were punished as investors took a doubtful view of earnings and stock valuations in light of potential increases to interest rates and the cost of capital going forward. Small caps lagged large caps, and within the small-cap space, growth stocks lagged value stocks. The Russell 2000 Growth Index -26.02% decline trailed the Russell 2000 Value Index's -10.73% return. That said, small-cap growth stocks outperformed the S&P 500 Index over the last

Calamos Timpani Small Cap Growth Fund   (Unaudited)

six months of the annual period—perhaps an indication that the sell-off in the space was overdone relative to the broad market.

For the full annual period within the Russell 2000 Growth Index, energy was the big winner with a 33% gain because of global supply concerns. The defensively oriented consumer staples (-7%) sector, materials (-8%), utilities (-13%) and industrials (-16%) each outperformed the benchmark, whereas financials (-27%), consumer discretionary (-30%), health care (-33%), information technology (-33%), real estate (-38%), and communication services (-41%) all lagged the index.

The Fund's performance received a boost from sector allocation decisions. The portfolio began the period with an overweight to the energy sector and maintained it over the course of the annual period, though we selectively added or reduced individual names throughout the course of the year. Because energy was the top-performing sector for the period, the overweight was strongly positive. Our view that long periods of underinvestment in energy business would create strong demand for equipment and services businesses as well as drillers came to fruition. The portfolio's underweight to the lackluster health care sector was also additive to relative performance, most notably an underweight to the biotechnology industry.

Security selection most negatively affected relative performance for the period. Market sentiment changed dramatically around high-growth businesses at the start of the annual period. Companies that had seen strong relative outperformance largely because of strong growth were punished most significantly during the annual period. Often, these businesses delivered strong earnings and revenues during their quarterly announcements, but the market grew skeptical about the prospects for higher growth businesses going forward. Security selection within health care, industrials, and information technology detracted from performance relative to the Russell 2000 Growth Index, though selection within financials was strongly additive. The market assigned a massive and negative rerating to growth businesses across equity markets but was most negative within the small-cap growth space. Broadly speaking, small-cap growth companies that delivered strong quarterly earnings announcements saw their stock prices tumble, and those that did not deliver or gave cautious outlooks were discounted even more significantly. As mentioned previously, the tide began to shift in the second half of the annual period as the Fund and small-cap growth stocks outperformed the broad market represented by the S&P 500 Index.

How is the Fund positioned?

For sector positioning, the most notable changes that occurred from the beginning of the annual period until its close involved increases to health care and consumer staples, with a decrease to consumer discretionary. In addition, energy went from a significant overweight at the start of the period to a modest overweight. Thanks to new additions within health care, the sector migrated from a significant underweight at the beginning of the period to a significant overweight. Health care additions included new, disruptive devices or treatments, which further spurred on already favorable growth in these spaces. Although consumer staples can be thought of as more defensive, we have selectively added to the sector in more dynamic growth areas rather than traditional, defensive, and low-growth consumer staples names.

We continue to hold investments in both long-term secular growth stocks and certain cyclical growth stocks that should benefit meaningfully from a continued economic uptick.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Timpani Small Cap Growth Fund   (Unaudited)

What closing thoughts do you have for Fund shareholders?

There are many signs the economy is slowing. The ongoing debate relates to the potential magnitude of future weakness. There are some bright spots for the broad market, especially relating to small-cap growth stocks. For one, we believe that inflation has likely peaked, and typically that has triggered a rally in stocks over the next 12 months, with or without a recession. Specifically, since 1942, there have been 17 spikes in inflation and the S&P 500 Index has rallied an average of 13.2% over the following 12 months after each spike, gaining 17.2% in the absence of a recession (nine of 17 occasions) and 8.8% with a recession (eight of 17 occasions).

In addition, seasonality has moved from negative to positive, although we expect volatility to continue. Since 1982, stocks have typically rallied beginning 26 business days prior to the November midterm elections (source: RBC). This year, we saw the market move upward starting in mid-October. Also, stocks historically have tended to rally over the six-month and 12-month periods after the midterm elections, with small caps and micro caps leading. This time, according to data from the Leuthold Group, small caps and microcaps also happen to be entering this period with extremely low relative valuations.

Another important point is we have invested through big drawdowns like this before and believe we are advantageously positioned for a snapback over the long term. Our portfolio is also smaller cap than our benchmark. Therefore, if conditions normalize and small caps assume a leadership role in line with the long-term historical trend, we believe our portfolio will be well positioned.

These are certainly intriguing statistics, but we would note that each cycle brings its own dynamics. This time, for the rally to begin and be sustained, we likely need bond yields to settle down and the Federal Reserve to become less hawkish at the margin.

ANNUALIZED RETURN: SINCE INCEPTION (3/23/11) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A, Class C and Class R6 shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Timpani Small Cap Growth Fund   (Unaudited)

GROWTH OF $1,000,000: SINCE INCEPTION (3/23/11) THROUGH 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.37%, Class C shares is 2.11%, Class I shares is 1.11% and Class R6 shares is 1.02%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023, to the extent necessary so that Total Annual Fund Operating Expenses of Class A, Class C and Class I shares are limited to 1.30%, 2.05%, 1.05% of average net assets, respectively. The Fund's investment adviser has contractually agreed to limit the Fund's annual ordinary operating expenses for Class R6 shares (as a percentage of average net assets) to 1.05% less the Fund's annual sub-transfer agency ratio (the aggregate sub-transfer agency fees of the Fund's other share classes divided by the aggregate average annual net assets of the Fund's other share classes). For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective share class's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

Effective as of the close of business on May 31, 2019, the Fund acquired all of the assets, subject to the liabilities, of the Timpani Small Cap Growth Fund (the "Predecessor Fund") through a tax-free reorganization (the "Reorganization"). Pursuant to the Reorganization of the Predecessor Fund into the Fund, Class Y shareholders of the Predecessor Fund received Class A shares of the Fund, and Service Class and Institutional Class shareholders of the Predecessor Fund each received Class I shares of the Fund. As a result of the Reorganization, the Fund adopted the performance and financial history of the Predecessor Fund. Accordingly, the performance shown in the average annual total return table above for periods prior to the commencement of the Fund's operations on June 1, 2019 is the performance of the Predecessor Fund. The Fund has the same investment objective, strategy and portfolio manager as the Predecessor Fund. As a result, the performance of the Fund would have been substantially similar to that of the Predecessor Fund.

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The Russell 2000 Growth Index is a composite of small-cap companies located in the US that also exhibit a growth probability.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Timpani SMID Growth Fund   (Unaudited)

OVERVIEW

The Fund invests in the equity securities of small- and mid-capitalization (SMID) companies with high, sustainable growth potential, which may exceed market expectations.

KEY FEATURES

^◼  Combines fundamental research with the analysis of market estimates to identify the underestimated growth differential between a company's business strength and market expectations of that strength.

^◼  Pursues active management in a less-followed investment space.

^◼  Analyzes secular trends to uncover exploitable investment opportunities specific to small- and mid-cap companies.

PORTFOLIO FIT

Investing in SMID companies is an important component of a diversified investment strategy. Small-to-midsize companies tend to experience greater growth and outperform larger companies, yet this greater potential also raises the potential for greater volatility—which is why we believe active management is crucial.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS TIMPANI SMID GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12-months ended October 31, 2022 ("annual period"), Calamos Timpani SMID Growth Fund posted a return of -36.95% (Class I Shares at net asset value), trailing the -27.38% loss for the Russell 2500 Growth Index.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take in an effort to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer duration equities (businesses whose values significantly depend on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period had raised rates five times for a total of 300 basis points while pointing to additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, although the decline has been interrupted by several strong rallies, which offered hope that the worst of economic fears may have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally, in advance of a significant and contentious midterm election in the United States. Adding to investors' woes over the annual period, the bond market delivered difficult performance as evidenced by the Bloomberg US Aggregate Bond Index's -15.68% return.

Small-cap stocks started their decline in November, a bit earlier than the broad market as represented by the S&P 500 Index. Macro concerns dominated investor sentiment as many small company stocks, especially growth stocks, saw share prices decline despite favorable earnings reports and positive company guidance. Companies that had exhibited strong growth and stock performance previously were punished as investors took a doubtful view of earnings and stock valuations in light of potential increases to interest rates and the cost of capital going forward. Small caps lagged large caps, and within the small-cap space, growth stocks lagged value stocks. The Russell 2500 Growth Index -27.38% decline trailed the Russell 2500 Value Index's -10.66% return. That said, small-cap growth stocks did outperform the S&P 500 Index over the last six months of the annual period—perhaps an indication that the sell-off in the space was overdone relative to the broad market.

For the full annual period within the Russell 2500 Growth Index, energy was the big winner with a 39% gain because of global supply concerns. The defensively

Calamos Timpani SMID Growth Fund   (Unaudited)

oriented utilities (-7%) and consumer staples (-15%) sectors also fared better than market, whereas materials (-16%), industrials (-20%), and financials (-22%) each outperformed the benchmark, and real estate (-28%), information technology (-31%), consumer discretionary (-32%), health care (-36%) and communication services (-42%) all lagged the index.

The Fund's performance received a boost from sector allocation decisions. The portfolio began the period with an overweight to the energy sector and maintained it over the course of the annual period, although we selectively added or reduced individual names throughout the course of the year. Because energy was the top-performing sector for the period, the overweight was strongly positive. Our view that long periods of underinvestment in energy business would create strong demand for equipment & services businesses as well as drillers served the portfolio well, even before the Russia-Ukraine war and supply disruptions came to the fore. The portfolio's underweight to the lackluster health care sector was also additive to relative performance, most notably an underweight to the biotechnology industry.

Security selection was the overarching detractor to relative performance for the period. Market sentiment changed dramatically around high-growth businesses at the start of the annual period. Companies that had seen strong relative outperformance largely because of strong growth were punished most significantly during the annual period. Often these businesses were able to deliver strong earnings and revenues during their quarterly announcements, but the market grew skeptical about the prospects for higher growth businesses going forward. Security selection within information technology, health care and industrials detracted from performance relative to the Russell 2500 Growth Index, although selection within financials was strongly additive. The market assigned a massive and negative rerating to growth businesses across equity markets but was most negative within the small-cap growth space. Broadly speaking, small-cap growth companies that delivered strong quarterly earnings announcements saw their stock prices tumble, and those that did not deliver or gave cautious outlooks were discounted even more significantly. As mentioned previously, the tide began to shift in the second half of the annual period as the Fund and small-cap growth stocks outperformed the broad market represented by the S&P 500 Index.

How is the Fund positioned?

Regarding sector positioning, the most notable changes that occurred from the beginning of the annual period until its close involved increases to health care and consumer staples with a decrease to consumer discretionary and information technology. In addition, energy grew as an absolute weight but remained fairly stable as an overweight during the period. Within health care, the sector migrated from a significant underweight at the beginning of the period to a significant overweight. Health care additions included new and disruptive devices or treatments, and this follows on the heels of already favorable growth in these spaces. Although consumer staples can be thought of as more defensive, we have selectively added to the sector in more dynamic growth areas rather than traditional, defensive and low-growth consumer staples names.

We continue to hold investments in both long-term secular growth stocks and certain cyclical growth stocks that should benefit meaningfully from a continued economic uptick.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Timpani SMID Growth Fund   (Unaudited)

What closing thoughts do you have for Fund shareholders?

There are many signs the economy is slowing. The ongoing debate relates to the potential magnitude of future weakness. There are some bright spots for the broad market, especially relating to small-cap growth stocks. For one, inflation has likely peaked; and typically, that has triggered a rally in stocks over the next 12 months, with or without a recession. Specifically, since 1942, there have been 17 spikes in inflation and the S&P 500 Index has rallied an average of 13.2% over the following 12 months after each spike, gaining 17.2% in the absence of a recession (nine of 17 occasions) and 8.8% with a recession (eight of 17 occasions).

In addition, seasonality has moved from negative to positive, although we expect volatility to continue. Since 1982, stocks have typically rallied beginning 26 business days prior to the November midterm elections (source: RBC). This year, we saw the market move upward beginning in mid-October. Also, stocks historically have tended to rally over the 6-mnth and 12-month periods after the midterm elections, with small caps and micro caps leading. This time, according to data from the Leuthold Group, small caps and microcaps also happen to be entering this period with extremely low relative valuations.

Another important point is that we have invested through big drawdowns like this before and believe we are advantageously positioned for a snapback in the long term. Our portfolio is also smaller cap than our benchmark. Therefore, if conditions normalize and small caps assume a leadership role in line with the long-term historical trend, we believe our portfolio will be well positioned.

These are certainly intriguing statistics, but we would note that each cycle brings its own dynamics. This time, for the rally to begin and be sustained, we likely need bond yields to settle down and the Federal Reserve to become less hawkish at the margin.

Calamos Timpani SMID Growth Fund   (Unaudited)

GROWTH OF $1,000,000: SINCE INCEPTION (7/31/19) THROUGH 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.79%, Class I shares is 1.55% and Class R6 shares is 1.48%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023 to the extent necessary so that Total Annual Fund Operating Expenses of Class A shares and Class I shares are limited to 1.35% and 1.10% of average net assets, respectively. The Fund's investment adviser has contractually agreed to limit the Fund's annual ordinary operating expenses for Class R6 shares (as a percentage of average net assets) to 1.10% less the Fund's annual sub-transfer agency ratio (the aggregate subtransfer agency fees of the Fund's other share classes divided by the aggregate average annual net assets of the Fund's other share classes). For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective share class's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares.

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The Russell 2500 Growth Index measures the performance of the small to mid-cap growth segment of the US equity universe. It includes those Russell 2500 companies with higher growth earning potential. The Russell 2500 Growth Index is published and maintained by FTSE Russell.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Growth Fund   (Unaudited)

OVERVIEW

A broad, flexible strategy enables the Fund to invest in the equities of US companies across all market capitalizations and sectors in order to attain the best potential for long-term capital growth.

KEY FEATURES

^◼  Seeks to provide attractive returns through an emphasis on higher-growth US companies spanning the full range of market capitalizations and sectors. Draws on more than three decades of experience in growth investing.

^◼  The portfolio reflects top-down, secular thematic views along with high-conviction, fundamentally researched stocks of companies with advantaged business models, high returns on capital, solid free-cash-flow generation, and stewardship-minded management.

^◼  Combines secular and cyclical growth to help manage the dynamics of the economy.

PORTFOLIO FIT

May be an attractive option for investors seeking higher growth and diversification that spans all caps of US companies across sectors and industries.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12-month period ended October 31, 2022 ("annual period"), Calamos Growth Fund returned -30.43% (Class I shares at net asset value), lagging the S&P 1500 Growth Index return of -23.88%. Market conditions changed dramatically from the prior one-year period, during which the Fund returned 46.40%.

Since the inception of Class I shares on September 18, 1997, the Fund has returned 10.36% on an annualized basis. The S&P 1500 Growth Index, the primary benchmark, returned 8.21% over the same period, and the S&P 500 Index returned 7.75%. We believe these comparisons demonstrate the Fund's ability to outdistance the growth and broad indices over full market cycles.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer duration equities (those businesses whose values significantly depend on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but most notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period, it had raised rates five times for a total of 300 basis points while pointing to additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, though the decline has been interrupted by several strong rallies, which offered hope that the worst economic fears might have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally, in advance of a significant and contentious midterm election in the United States. Adding to investors' woes over the annual period, the bond market delivered stomach-churning performance as evidenced by the Bloomberg US Aggregate Bond Index's -15.68% return.

Within the S&P 1500 Growth Index, only three sectors were able to post positive returns for the period: energy (though little more than 1% of the index weight) gained 52% on supply concerns, whereas more defensively oriented utilities (+5%) and consumer staples (+2%) also gained as investors sought to reduce risk. Materials (-7%), health care (-12%), industrials (-15%), financials (-18%), real estate (-21%) and information technology (-22%) each outperformed the index, while consumer discretionary (-33%) and communication services (-48%) significantly lagged.

Calamos Growth Fund   (Unaudited)

Security selection within the financials sector was additive to relative Fund performance for the period. Specifically, our holdings in regional banks and consumer finance represented major contributors. Security selection within the health care sector also boosted results, notably holdings in pharmaceuticals and managed health care. The Fund's average overweight to the health care sector was also supportive on a relative basis. The Fund started the period at an underweight relative to the benchmark index but saw its health care weight increase over the course of the year.

Individual position selection within information technology was the Fund's biggest detractor to relative performance. Holdings in the internet services & infrastructure and the technology hardware, storage & peripherals industries lagged on a relative basis. Additionally, an underweight to the sector over the course of the period slightly detracted because the sector was a marginal outperformer for the period, despite the market's general preference away from growthier and long-duration sectors. Communication services holdings slightly lagged those of the benchmark. Security selection within the movies & entertainment and the interactive media & services industries of the sector hurt relative returns. Selection in the industrials sector also hindered performance over the period.

How is the Fund positioned?

As we have noted previously, we continue to see many attractive opportunities in what we call "fortress growth" companies that have been unduly caught up in the broader sell-off. These are industry champions that offer well-established economic moats and should provide reliable cash flow generation for years to come. We are also maintaining our investments in a handful of smaller-cap, dynamic growth names that should generate outsized revenue and profit growth, despite a potentially weakening US economy. In many cases these smaller-cap names have been sold off to extremely low relative valuations yet still offer strong growth opportunities.

The Fund did raise its allocation to more defensive consumer staples during the period and also saw an increase to health care—a sector in which many companies' cash flows are less dependent on high or accelerating GDP growth. That said, it should be noted that the valuations of defensive areas of the market are trading at premiums relative to cyclical areas based on forward price-to-earnings ratios. As such, the Fund continues to own a mix of growth opportunities. As always, we continue to believe that prudent stock selection, constant risk management, and patience are the keys to success in markets such as these.

What closing thoughts do you have for Fund shareholders?

Volatile markets are never easy, and we expect many investors will be surprised that, despite the ups and downs and tremendous negative sentiment, the last third of the annual period saw a marginally positive yet volatile period for Fund and market performance. Looking ahead, we are confident the current wall of worry will be less severe than feared. Interest rates are expected to end the year around 4.00% to 4.25%, but we believe that future rate hikes should be more modest from there. Supply chains are healing rapidly, and inventory levels are now healthy. At the same time, consumers still have relatively strong balance sheets, and the job market remains healthy overall. All these conditions should lay the foundation for solid, even if more muted, earnings growth going forward.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Growth Fund   (Unaudited)

At the time of this writing, we've just passed the midterm elections. Though the final outcomes are still to be determined, it appears that the US will have a divided or balanced Congress, which typically translates to more moderate government actions—traditionally a positive from the market's point of view. Historically, this is seasonally a stronger period for equity markets—the period just before and well after midterm elections. While these factors both speak well for markets, we believe volatility will remain elevated as the European energy crisis and broader economic impacts from a still-recovering, zero-Covid-19 China plays out. Inflation appears to have peaked, though it will likely take a few months or quarters to return to more normal levels. We believe that long-term investors will look back and realize that the earnings power of US growth companies were not permanently damaged. America remains one of the most dynamic financial markets in the world, and we don't believe that will change. As interest rates stabilize and earnings growth resumes, we believe the rally in growth stocks will as well.

ANNUALIZED RETURN: SINCE INCEPTION (9/18/97) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Growth Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

Performance results do not include adjustments made for financial reporting purposes in accordance with US generally accepted accounting principles and may differ from amounts reported in the financial highlights.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.28%, Class C shares is 2.04% and Class I shares is 1.03%. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The S&P 1500 Growth Index consists of the growth segment of the securities found in the S&P 1500 Index. The S&P 1500 combines the S&P 500, S&P MidCap 400 and the S&P SmallCap 600.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Growth and Income Fund   (Unaudited)

OVERVIEW

The Fund invests primarily in US equity and convertible securities in an attempt to balance risk/reward while providing growth and income.

KEY FEATURES

^◼  Leverages more than four decades of research experience combining equities and convertible holdings to provide equity-like participation.

^◼  Provides a core holding option that aims to maintain a consistent risk posture throughout the market cycle.

^◼  Research-driven approach identifies opportunities by combining top-down analysis with a focus on key growth characteristics.

PORTFOLIO FIT

The Fund can provide a long-term core equity allocation, which exhibits potentially lower volatility and delivers attractive income.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS GROWTH AND INCOME FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Growth and Income Fund posted a return of -15.55% (Class I Shares at net asset value). In comparison, the S&P 500 Index returned -14.61%, and the ICE BofA All US Convertibles ex Mandatory Index registered a loss of -21.86% for the annual period. We manage this Fund with the goal of achieving upside equity participation and potential downside risk mitigation over full market cycles. For the annual period, Calamos Growth and Income Fund captured 86% of the all-equity index's returns. Since its Class I shares inception on September 18, 1997, the Fund has returned 9.38% on an annualized basis versus a 7.75% gain for the S&P 500 Index and an 8.03% return for the ICE BofA All US Convertibles ex Mandatory Index.

Please discuss the Fund's lower-volatility characteristics.

We believe the Fund's historical lower volatility characteristics are a by-product of our investment style and focus on participating in equity market upside with less volatility than the market as a whole. Beta is one popular statistic for measuring volatility. Beta considers a fund's historic volatility versus the market, which is assigned a beta of 1.0. A fund with half the volatility of the market would have a beta of 0.5, whereas a fund with a beta of 2.0 would have been twice as volatile as the market. Since its inception, the Fund has had a beta of 0.76 (Class I shares) versus the S&P 500 Index. The Fund, therefore, outperformed the broader equity market as measured by the S&P 500 Index and with less volatility. Please note that past performance does not indicate future results and that beta is one of many measures of risk.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take in an effort to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer duration equities (those businesses whose values significantly depend on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period had raised rates five times for a total of 300 basis points while pointing to additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, although the decline has been interrupted by several strong rallies that offered hope that the worst economic fears may have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally in advance of a significant and contentious US midterm election. Adding to investors' woes over the period, the bond market delivered a difficult performance as evidenced by the Bloomberg US Aggregate Bond Index's -15.68% return.

Calamos Growth and Income Fund   (Unaudited)

Convertible securities also saw a precipitous decline of -17.07% for the period, as reported above. Although convertible securities historically haven't declined more than the broad equity market, investors were highly averse to small to mid-sized growth companies during the annual period, and the underlying equities of convertible issuers (which lean heavier toward small and mid caps) saw a drop of approximately -37% during the 12-month period—similar to the performance of small-cap or mid-cap growth equity indices. When measured against the underlying equities, convertible securities did offer more traditional downside resilience. More recently, convertible securities have participated to a higher degree in a more traditional pattern relative to the broad equity market as small and mid-sized growth businesses have been under less intense selling pressure than they were during the first few months of this annual period.

Within the equity market, value stocks were more in favor over the period, as noted earlier. The S&P 500 Value Index declined -3.66% for the past 12 months, whereas the S&P 500 Growth Index fell -24.43%, and the overall S&P 500 Index returned -14.61%. In the S&P 500 Index, energy was the big winner with a 65% return as a result of global supply concerns. More defensively oriented areas, such as consumer staples (+5%) and utilities (+3%) fared well, whereas health care (+1%) also finished in positive territory for the period. Industrials (-8%), materials (-11%) and financials (-14%) led the overall index, whereas information technology (-20%), real estate (-21%), consumer discretionary (-29%) and communication services (-41%) lagged.

For the 12-month annual period, the Fund slightly lagged the all-equity index because of issue selection with a slight bias toward quality growth stocks versus a market that rewarded more value-oriented stocks. As mentioned, the period was an uncharacteristically difficult period for convertible bonds relative to the broad equity market, although convertible preferred securities held in the portfolio did contribute to relative performance. From a sector allocation perspective, the portfolio's overweight to energy, the equity market's leading sector, was additive as was an underweight to information technology and a temporarily higher level of cash in light of difficult market conditions. Conversely, an underweight to health care and an overweight to communication services detracted from a sector perspective. At the individual position level, selection within health care and financials lagged those of the all-equity index. Health care holdings in pharmaceuticals gained handsomely but lagged those of the all-equity index, and financials sector investments in multi-sector holdings life & health insurance held back return.

How is the Fund positioned?

We believe the best positioning for this environment remains a defensive posture with a focus on lower-risk businesses that offer lower beta, high-quality balance sheets and higher return on capital. Areas such as health care, lower beta staples, defense, software (cyber defense and system software) and parts of telecom provide some of those attributes. We have been positive on the supply/demand environment for energy, but we are turning somewhat cautious as global growth slows. From an asset class perspective, cash and short-term Treasuries are now a useful tool to lower volatility in a multi-asset class portfolio, given their current positive yields. Despite elevated absolute volatility, we are selectively using options to gain some cyclical exposure in case our watch factors surprise to the upside.

What closing thoughts do you have for Fund shareholders?

In challenging economic and market environments, we believe that balancing the long- and short-term outlooks provides the best insights for portfolio positioning.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Growth and Income Fund   (Unaudited)

Focusing on either one exclusively can lead to overly optimistic or pessimistic positioning that may not be warranted in the volatile markets.

We remain confident that the positive long-term growth trajectory of the US economy and the cash flow generation capabilities of US companies remain intact. The ability of management teams to seek to identify emerging short- and long-term trends and the adaptability of business models and cost structures are central to our long-term favorable view. We see attractive long-term upside in the US equity market from current market levels, which we view at fair value or below fair value for a majority of US companies.

In the short term, the extreme conditions (both positive and negative) that occurred during the past two years dominated by the pandemic have not yet reverted to a more normal environment or to the long-term mean. Since mid-2021 our expectation has been for a lower growth environment in 2022 and 2023. This slower growth outlook has been exacerbated by the war in Ukraine and China's Covid-19 shutdowns. These two factors also have worsened the inflation environment, causing most central banks around the world to raise interest rates, which should further slow growth. As we have seen so far in 2022, slowing growth, high inflation and rising interest rates have led to significant declines in asset prices. We have yet to see significant reductions in earnings estimates, but we can expect that to occur in the near term for any number of reasons.

A mean reversion transition needs to occur for the challenging short-term environment to migrate to the more normalized long-term trend. We are watching several factors that would indicate this trend is occurring. Those factors include improved labor market participation; a normalization of consumer spending versus income, including lower real goods consumption; lower retail inventory levels; improved supply chains for certain areas of manufacturing; improved supply/demand for commodities (oil and food); central banks slowing their restrictive policies; resumption of activity in China; and a reduction in military activity in Ukraine. This list is long, and many of these factors may take a long time to sort out. However, the equity markets are forward looking, so improvement in any of these factors should be positive for asset markets.

ANNUALIZED RETURN: SINCE INCEPTION (9/18/97) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A, Class C and Class R6 shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Growth and Income Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.06%, Class C shares is 1.81%, Class I shares is 0.81% and Class R6 shares is 0.73%. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares. Returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

The ICE BofA All US Convertibles EX Mandatory Index represents the US convertibles securities market excluding mandatory convertibles.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Dividend Growth Fund   (Unaudited)

OVERVIEW

The Fund invests in companies that we believe have the ability to increase dividends over time, either through increasing profits or more efficient use of capital.

KEY FEATURES

^◼  Employs bottom-up stock picking and a benchmark-agnostic approach.

^◼  Focuses on good businesses with solid cash flows and value prices.

PORTFOLIO FIT

The Fund may be suitable for investors seeking a regular stream of income and dividend-paying equity investments that tend to be less volatile than non-dividend payers.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS DIVIDEND GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Dividend Growth Fund returned -14.76% (Class I shares at net asset value), in line with the S&P 500 Index return of -14.61%.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take in an effort to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer-duration equities (those businesses whose values significantly depend on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, notwithstanding the human tragedies associated with the armed conflict. The war disrupted many facets of life, but most notably, from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period had raised rates five times for a total of 300 basis points while pointing toward additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, but the decline has been interrupted by several strong rallies, which offered hope that the worst economic fears may have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally in advance of a significant and contentious US midterm election. Adding to investors' woes, the bond market delivered difficult performance as evidenced by the Bloomberg US Aggregate Bond Index, registering a -15.68% return for the period.

Within the equity market, value stocks were more in favor over the period, as noted earlier. The S&P 500 Value Index declined -3.66% for the past 12 months, whereas the S&P 500 Growth Index fell -24.43%, and the overall S&P 500 Index returned -14.61%. In the S&P 500 Index, energy was the big winner with a 65% return on account of global supply concerns. More defensively oriented areas such as consumer staples (+5%) and utilities (+3%) fared well, whereas health care (+1%) also finished in positive territory for the period. Industrials (-8%), materials (-11%) and financials (-14%) led the overall index, whereas information technology (-20%), real estate (-21%), consumer discretionary (-29%) and communication services (-41%) all lagged.

The Fund's focus on higher cash flows and higher dividend yielding securities was a positive contributor to performance over the period, but a slight bias toward stocks with higher growth attributes as a result of sector decisions hindered performance in light of the market's preference for value stocks. From a sector perspective, decisions were a net positive to relative performance. The Fund was smartly overweight in the energy sector, which was the top-performing sector, and underweight in communication services, the worst-performing sector, which was also a positive relative contributor. A slight overweight to consumer discretionary

Calamos Dividend Growth Fund   (Unaudited)

stocks detracted from a sector perspective. Individual security selections were a net drag on relative performance. Selections in consumer discretionary hindered relative performance as growthier names struggled relative to the market, and holdings in the auto parts & equipment and general merchandise stores industries hurt relative returns. Selection in financials lagged those of the market, and multi-sector holdings and our nonparticipation in life & health insurance held back return.

How is the Fund positioned?

The Fund remains broadly diversified by sector, favoring investments in dividend-paying equities. Allocations to health care and energy rose during the period, with increased weights in pharmaceuticals and integrated oil & gas. By contrast, allocations to consumer discretionary and communication services decreased over the period with reductions to internet & direct marketing retail and interactive media & services. We continue to seek higher-quality businesses with dividends or dividend growth potential, which in our view should continue to serve the portfolio well in an uncertain market environment.

What closing thoughts do you have for Fund shareholders?

In challenging economic and market environments, we believe that balancing the long- and short-term outlooks provides the best insights for portfolio positioning. Focusing on either one exclusively can lead to overly optimistic or pessimistic positioning that may not be warranted in the volatile markets.

We remain confident that the positive long-term growth trajectory of the US economy and the cash flow generation capabilities of US companies remain intact. The ability of management teams to seek to identify emerging short- and long-term trends along with the adaptability of business models and cost structures are central to our long-term favorable view. We see attractive long-term upside in the US equity market from current market levels, which we view at fair value or below fair value for a majority of US companies.

In the short term, the extreme conditions (both positive and negative) of the past two years, dominated by the pandemic, have not yet reverted to a more normal environment or to the long-term mean. Since mid-2021, our expectation has been for a lower growth environment in 2022 and 2023. This slower growth outlook has been exacerbated by the war in Ukraine and China's Covid-19 shutdowns. These two factors have also worsened the inflation environment, causing most central banks around the world to raise interest rates, which should further slow growth. As we have seen so far in 2022, slowing growth, high inflation and rising interest rates have led to significant declines in asset prices. We have yet to see significant reductions in earnings estimates, but we can expect that to occur in the near term for any number of reasons.

A mean reversion transition needs to occur for the challenging short-term environment to migrate to a more normalized long-term trend. We are watching several factors that would indicate this trend is occurring. These include improved labor market participation; a normalization of consumer spending versus income, including lower real goods consumption; lower retail inventory levels; improved supply chains for certain areas of manufacturing; improved supply/demand for commodities (oil and food); central banks slowing their restrictive policies; resumption of activity in China; and a reduction in military activity in Ukraine. This list is daunting, and many of these factors may take a long time to sort out. However, the equity markets are forward looking, so improvement in any of these factors should be positive for asset markets.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Dividend Growth Fund   (Unaudited)

GROWTH OF $1,000,000: SINCE INCEPTION (8/05/13) THROUGH 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 2.04%, Class C shares is 2.78% and Class I shares is 1.80%. The Fund's Investment Adviser has contractually agreed to reimburse Fund expenses through 3/1/23 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses and extraordinary expenses, if any) of Class A, Class C and Class I shares are limited to 1.35%, 2.10%,1.10% of average net assets, respectively. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum frontend sales load of 4.75% for Class A shares. Returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graph does not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Select Fund   (Unaudited)

CALAMOS SELECT FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12-months ended October 31, 2022 ("annual period"), Calamos Select Fund returned -16.00% (Class I shares at net asset value), trailing the S&P 500 Index return of -14.61%.

What factors influenced performance during the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take in an effort to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants. As the Fed continued to raise inflation expectations while speaking more aggressively about interest rate hikes, longer duration equities (those businesses whose values significantly depend on high and growing cash flows over longer time frames) began to struggle in mid-to-late November 2021.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period, it had raised rates five times, totaling 300 basis points while pointing to additional aggressive hikes still to come.

The US equity market, as measured by the S&P 500 Index, peaked in early January, though the decline has been interrupted by several strong rallies, which offered hope that the worst economic fears may have already been priced into the market. At the end of the annual period, equity markets were in the midst of another solid rally in advance of a significant and contentious midterm election in the United States. Adding to investors' woes over the annual period, the bond market delivered difficult performance, as evidenced by the Bloomberg US Aggregate Bond Index's -15.68% return.

Within the equity market, value stocks were more in favor over the period, seen in the S&P 500 Value Index's modest -3.66% decline over the past 12 months, whereas the S&P 500 Growth Index fell -24.43%, and the overall S&P 500 Index declined -14.61%. Energy was the big winner in the S&P 500 Index because of global supply concerns, with a 65% return. More defensively oriented areas such as consumer staples (+5%) and utilities (+3%) fared well, and health care (+1%) also finished in positive territory for the period. Industrials (-8%), materials (-11%) and financials (-14%) led the overall index, whereas information technology (-20%), real estate (-21%), consumer discretionary (-29%) and communication services (-41%) lagged.

Overall, sector allocations were additive to the Fund's relative performance over the annual period, highlighted by an overweight to consumer staples and underweight to information technology. Although sector positioning was helpful, security selection within sectors caused a relative drag on performance. The portfolio favored names with higher growth opportunities and was not

OVERVIEW

The Fund primarily invests in a concentrated portfolio of large-cap US equities with broad representation across sectors and industries. In addition, the Fund can invest across investment styles in the US equity market.

KEY FEATURES

^◼  Security selection is based mainly on Calamos analysts' highest conviction ideas. We leverage the collective expertise of the firm's research analysts, who average 15+ years of experience in their areas of expertise.

^◼  The investment process is driven by rigorous fundamental and sector-specific research. The goal is to maximize exposure to opportunities the team believes are compelling.

^◼  Quantitative tools help minimize systematic risks across both sectors and factors. We use quantitative tools to minimize unintended bets and maximize the impact of security selection.

PORTFOLIO FIT

Because the Fund pairs a high-conviction approach with a broad investment universe, we believe it is an attractive choice for investors seeking a long-term core equity allocation to US stocks.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Select Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

overweight toward the outright cheap names in the index, which the market favored during the period. Security selection within the information technology sector, notably holdings in the internet services & infrastructure and semiconductors industries, underperformed during the period, given that investors shied away from higher growth stocks. Additionally, selection within the footwear and auto parts & equipment industries of the consumer discretionary sector lagged.

How is the Fund positioned?

At the end of the period, in terms of economic sectors, the largest portfolio weight resides in information technology. Yet this sector also represents our largest underweight to the S&P 500 Index because we remain selective within this commonly long-duration equity sector. At the period's end, we hold no names within the real estate sector. The Fund maintains its overweight allocations to consumer staples and industrials relative to the index. Food distributors and railroads represent the largest industry overweights within the respective sectors. Allocations to health care and energy rose during the period, with increased weights in pharmaceuticals and integrated oil & gas. By contrast, allocations to information technology and communication services decreased over the period, with reductions to application software and interactive media & services.

What closing thoughts do you have for Fund shareholders?

Volatile markets are never easy, and we expect many investors will be surprised that, despite the ups and downs and tremendous negative sentiment, the last third of the annual period was marginally positive yet volatile for Fund and market performance. Looking ahead, we are confident the current wall of worry will be less severe than feared. Interest rates are expected to end the year around 4.00% to 4.25%, but future rate hikes should be more modest from there. Supply chains are healing rapidly, and inventory levels are now healthy. At the same time, consumers still have relatively strong balance sheets, and the job market remains healthy overall. All of these conditions should lay the foundation for solid, if more muted, earnings growth going forward.

At the time of this writing, we've just passed the midterm elections. Though the final outcomes are still to be determined, it appears that the United States will have a divided or balanced Congress, which typically translates to more moderate government actions—traditionally a positive from the market's point of view. Historically, this is a seasonally stronger period for equity markets—the period just before and well after midterm elections. Despite these potentially helpful developments, volatility will likely remain elevated as the European energy crisis and broader economic impact from a still-recovering zero-Covid China play out. Inflation appears to have peaked, though it will likely take a few months or quarters to return to more normal levels. We believe that long-term investors will look back and realize that the earnings power of US growth companies was not permanently damaged. America remains one of the most dynamic financial markets in the world. As interest rates stabilize and earnings growth resumes, we believe the rally in growth stocks will as well.

Calamos Select Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (3/1/02) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Performance shown reflects an expense reimbursement that improved results. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Select Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.57%, Class C shares is 2.33% and Class I shares is 1.32%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023, to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.15%, 1.90%, and 0.90% of average net assets, respectively. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The S&P 500 Index is an unmanaged index generally considered representative of the US stock market.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos International Growth Fund   (Unaudited)

CALAMOS INTERNATIONAL GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos International Growth Fund returned -36.54% (Class I shares at net asset value), versus a -29.35% return for the MSCI EAFE Growth Index and 24.35% return for the MSCI ACWI ex USA Index for the period. The Fund's return landed within the 78th percentile of the Morningstar Foreign Large Growth category during the annual period.*

Since its inception on March 17, 2005, the Fund has returned 6.12% on an annualized basis (Class I shares at net asset value) ahead of the 4.89% return for the MSCI EAFE Growth Index and the 4.32% return for the MSCI ACWI ex USA Index. We believe this demonstrates the Fund's ability to generate long-term excess returns over complete market cycles.

What factors influenced performance during the annual period?

International stocks faced a challenging environment over the annual period amid a backdrop of persistently higher inflation, rising interest rates, and heightened geopolitical tension. Looking forward, investors and companies have lowered expectations, reflecting risks around interest rates, high commodity costs, and slowing demand fundamentals. The Calamos International Growth Fund lagged the MSCI EAFE Growth Index over the period due to trailing relative security selection. Our holdings in foreign companies with secular and cyclical growth characteristics trailed the more defensive and dividend-oriented areas that held up relatively better amid the broad global equity sell-off.

The Fund's average overweight stance and favorable security selection in energy helped relative performance. In particular, positions in the integrated oil & gas industry and names in the oil & gas exploration & production industry delivered gains. Security selection in materials added to the Fund's performance, especially in the diversified metals & mining and copper industries.

Over the period, security selection and an average overweight allocation within the information technology sector hampered relative results. Holdings in the semiconductors and application software industries notably underperformed. Selection and an average overweight stance within the internet & direct marketing retail and auto parts & equipment industries of the consumer discretionary sector also curbed return.

From a geographic standpoint, the Fund's relative underweight in emerging markets contributed to performance over the period. Specifically, the Fund's underweight position in Emerging Asia and EMEA added value. On the flipside, the Fund's relative security selection in Emerging Asia and Japan detracted from relative results, as growth-oriented businesses in those markets trailed the benchmark.

*  Data as of 10/31/22. Morningstar category percentile ranking is based on annualized total return for the 1-year, 3-year, 5-year and 10-year periods. Calamos International Growth Fund Class I Shares were in the 78th, 11th, 36th and 57th percentiles of 444, 387, 346 and 223 funds for the 1-year, 3-year, 5-year and 10-year periods, respectively, for the Morningstar Foreign Large Growth category.

OVERVIEW

The Fund offers a dynamic approach to accessing international growth opportunities. We apply our active investment approach to build a portfolio of companies with superior growth and quality attributes across developed and emerging market.

KEY FEATURES

^◼  Identifies companies with compelling growth, competitive advantages and financial strength.

^◼  Identifies durable secular themes that provide a tailwind for sustainable growth and a franchise premium.

^◼  Investment universe spans geographies and market caps, providing a wide breadth of opportunities.

^◼  Takes environmental, social and governance (ESG) factors into account, evaluating the effects on a company's risk profile, cash flow and long-term returns.

PORTFOLIO FIT

As an active, true growth offering with a differentiated return profile, the Fund can potentially help investors optimize capital appreciation within their international allocation.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos International Growth Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

How is the Fund positioned?

The Fund's regional and country positioning reflects the combined inputs from our top-down global framework and our bottom-up security analysis. Our investment team evaluates macroeconomic factors and growth opportunities, actively integrating them into the investment decision-making process.

^◼  We positioned the Fund with a combination of secular and cyclical growth companies, commodity exposures, select defensives, and reopening opportunities. We are emphasizing companies with pricing power, positive earnings momentum, quality balance sheets, and attractive valuations.

^◼  Information technology, consumer discretionary and industrials are the largest sector weights. Key industry positions include pharmaceuticals, apparel & luxury goods, semiconductor equipment, diversified banks, aerospace & defense, internet retail, and integrated oil & gas.

^◼  We own holdings in energy and materials, with companies positioned to benefit from favorable supply-and-demand dynamics, attractive capital efficiency, and cash flow characteristics.

^◼  We have an underweight stance in more defensive areas, including utilities, real estate, consumer staples and traditional telecoms.

From a geographic perspective, we own diversified holdings in Europe with a blend of end markets and business types. Our positioning largely consists of higher-quality global businesses that sustain strong balance sheets and demonstrate less reliance on demand in Europe. We own companies in Japan with durable business models, positioned to benefit from improving exports and relative earnings momentum. We own positions in emerging markets across a diverse set of economies and within key demand areas, including semiconductor equipment, interactive media, and higher-quality financials.

What closing thoughts do you have for Fund shareholders?

International stocks continue to confront a set of complex crosscurrents. We are analyzing many aspects of economic activity, alongside evolving policy actions, corporate earnings, and geopolitical factors. With persistent global inflation and tighter monetary policy, the financial markets remain uncertain, and we expect global volatility will continue until these risks resolve. Within this complicated environment, we seek to identify ways to capitalize on volatility, including a range of opportunities at the thematic, regional and market-cap level.

In terms of Fund positioning, we emphasize companies with favorable pricing power, stronger earnings momentum, quality balance sheets and attractive valuations. From a sector perspective, we see opportunities in technology, industrials, health care, financials, consumer discretionary, and energy with compelling fundamentals. We believe our active investment approach and long-term perspective positions us to take advantage of the volatility and opportunities in international markets.

Calamos International Growth Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (3/16/05) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A, Class C and Class R6 shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos International Growth Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^†

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.56%, Class C shares is 2.31%, Class I shares is 1.31% and Class R6 shares is 1.22%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.10%, 1.85%, and 0.85% of average net assets, respectively. The Fund's investment adviser has contractually agreed to limit the Fund's annual ordinary operating expenses for Class R6 shares (as a percentage of average net assets) to 0.85% less the annual sub-transfer agency ratio for the Fund. The annual sub-transfer agency ratio is equal to the aggregate sub-transfer agency expenses common to the other share classes of the Fund divided by the aggregate average annual net assets of the Fund's other share classes. For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, all commissions and other normal charges incident to the purchase and sale of portfolio securities, and extraordinary expenses, if any. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The MSCI EAFE Growth Index measures developed market growth equity performance (excluding the US and Canada).

The MSCI ACWI ex USA Index represents the performance of large- and mid-cap stocks across developed and emerging markets excluding the United States. The MSCI ACWI ex USA Index is provided to show how the Fund's performance compares with the returns of an index of securities similar to those in which the Fund invests.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Evolving World Growth Fund   (Unaudited)

CALAMOS EVOLVING WORLD GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Evolving World Growth Fund returned -34.39% (Class I shares at net asset value) versus a -30.73% return for the MSCI Emerging Markets Index. Since its Class I shares inception on August 15, 2008, the Fund has returned 3.53% on an annualized basis compared with the 1.31% return of the MSCI Emerging Markets Index. We believe this demonstrates the Fund's ability to access emerging market opportunities and deliver leading returns while pursuing a risk-managed investment approach over complete market cycles

What factors influenced performance during the annual period?

Emerging markets struggled during the annual period against a backdrop of persistently higher inflation, tighter monetary policy, a strong dollar and geopolitical tension. Looking forward, investors and companies have lowered expectations in response to risks concerning interest rates, high commodity costs, and slowing demand fundamentals.

Pursuant to our strategies, the Calamos Evolving World Growth Fund navigated the volatile global markets by employing an active blend of economic cohorts across a wide investment universe. The Fund's return trailed the index over the 12-month period due primarily to relative security selection. Our holdings in emerging market companies with secular and cyclical growth characteristics trailed the more defensive and value-oriented market areas that held up relatively better amid the significant sell-off in emerging markets.

The Fund's favorable security selection in energy helped buoy relative returns. In particular, our holdings in the integrated oil & gas and oil & gas exploration & production industries represented major contributors. Leading security selection in consumer staples added to the Fund's performance. Holdings in soft drinks and hypermarkets & super centers were the main contributors.

Over the period, security selection and an average underweight stance within the information technology sector detracted from relative performance. Holdings in semiconductors and IT consulting & other services lost ground on a relative basis. Selection in communication services held back return. Specifically, holdings in interactive home entertainment and our lack of representation in integrated telecommunication services hindered results.

From a geographic standpoint, the Fund benefitted from leading security selection and an underweight allocation in EMEA. In contrast, the Fund's security selection in Emerging Asia hampered returns. Specifically, our holdings in Taiwan and China trailed their peers in the benchmark, as growth-oriented names underperformed in the period. In addition, security selection in Emerging Latin America dampened relative results, while our average overweight position was supportive.

OVERVIEW

The Fund offers an active, risk-managed strategy to access growth opportunities in emerging markets. The Fund invests in emerging market-domiciled and developed market-domiciled companies with significant revenue exposures attributable to emerging markets.

KEY FEATURES

^◼  Focuses on higher-quality companies with compelling growth attributes.

^◼  Conducts research across the capital structure and utilizes Calamos' experience in convertible securities to dynamically manage the risk profile.

^◼  Emphasizes countries enacting structural reforms and improving economic freedoms, which we believe enhances growth prospects and mitigates risk.

^◼  Identifies durable secular themes that provide a tailwind for sustainable growth and a franchise premium.

PORTFOLIO FIT

Because of its focus on risk management, the fund can serve as a long-term emerging-market allocation.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Evolving World Growth Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

How is the Fund positioned?

We maintain a vigilant but constructive view on medium-term opportunities in emerging markets. Our Fund positioning favors a blend of secular and cyclical growth companies, in addition to commodity exposures, reopening opportunities and select defensives. From a sector perspective, the largest weights reside in financials, consumer discretionary and information technology. We own holdings within key demand areas, including high-quality financials, internet retail, semiconductors, interactive media & services, apparel & luxury goods, and aerospace. We hold low weights or underweights in utilities and traditional telecoms. From a geographic perspective, we favor investments in India, Brazil, select names in China and increased opportunities in Southeast Asia and the Middle East.

What closing thoughts do you have for Fund shareholders?

Emerging markets continue to navigate a set of complex crosscurrents. We are analyzing many aspects of economic activity, evolving central bank policy, corporate earnings, and geopolitical factors. With inflationary pressures persisting and monetary policy tightening, markets remain uncertain, and we expect equity volatility to continue until these risks resolve. Despite this complicated backdrop, we seek to identify ways to capitalize on volatility, including a range of opportunities at the sector and thematic levels.

In terms of Fund positioning, we favor companies with pricing power, strong earnings momentum and high-quality balance sheets. From a sector perspective, we see opportunities in consumer discretionary, financials, information technology, industrials, and energy with attractive bottom-up fundamentals. We believe that our active investment approach and long-term perspective position us to take advantage of the volatility and opportunities in emerging markets.

Calamos Evolving World Growth Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (8/15/08) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Evolving World Growth Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.60%, Class C shares is 2.34% and Class I shares is 1.35%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.30%, 2.05%, and 1.05% of average net assets, respectively. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graph does not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The MSCI Emerging Markets Index is a free float-adjusted market capitalization index considered broadly representative of emerging market equity performance. The index represents companies within the constituent emerging markets that are available to investors worldwide. The index is calculated on a total return basis, which includes reinvestment of gross dividends before deduction of withholding taxes.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund's use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

Calamos Global Equity Fund   (Unaudited)

CALAMOS GLOBAL EQUITY FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Global Equity Fund returned -29.20% (Class I shares at net asset value) versus an -18.09% return for the MSCI World Index and -19.58% return for the MSCI ACWI Index. The Fund's return finished ahead of its category peer average in the period, landing in the 49th percentile of the Morningstar Global Large Stock Growth category.*

We believe the Fund's compelling medium and long-term performance record demonstrates its ability to generate excess returns over complete market cycles and varied investment environments. Since its inception on March 2, 2007, the Fund has returned 7.66% on an annualized basis (Class I shares at net asset value) compared with a 6.12% return for the MSCI World Index and 5.66% return for the MSCI ACWI Index.

What factors influenced performance during the annual period?

Global stocks struggled over the annual period amid a backdrop of higher inflation, rising interest rates and heightened geopolitical tension. Looking forward, investors and companies have lowered expectations in light of risks concerning interest rates, high commodity costs, and slowing demand fundamentals. The Fund trailed the index over the period due to trailing relative security selection. Many of our Fund holdings in global companies with cyclical and secular growth characteristics trailed the more defensive and dividend-oriented market areas that held up relatively better amid the broad sell-off.

The Fund's average overweight stance and favorable security selection in energy promoted relative results. Our holdings in the oil & gas exploration & production and integrated oil & gas industries added to return. An average underweight allocation in industrials also helped performance. The main contributors within this sector were construction & engineering and industrial machinery positions.

Over the period, security selection and an average overweight allocation within the information technology sector held back relative returns. Holdings in the semiconductors and semiconductor equipment industries lagged on a relative basis. Selection and an average overweight position in consumer discretionary, specifically in the apparel, accessories & luxury goods and the casinos & gaming industries, lost ground on a relative basis.

From a geographic standpoint, favorable security selection in Emerging Latin America aided results. Specifically, our holdings in Brazil promoted returns. In contrast, security selection in Emerging Asia hindered relative performance.

OVERVIEW

The Fund invests in equities of companies around the globe. We seek firms demonstrating what we believe to be key growth characteristics, including increasing profit margins and high returns on invested capital.

KEY FEATURES

^◼  Flexibly seeks growth globally, searching for the best risk/reward opportunities across countries, market capitalizations and sectors.

^◼  Seeks global growth companies that may benefit from long-term secular themes, including a burgeoning global middle class and increasing demand for information and entertainment.

PORTFOLIO FIT

The Fund can serve as a growth-oriented addition to a strategic global equity allocation and may complement or provide an alternative to value or blended styles.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

*  Data is as of 10/31/22. The Morningstar category percentile ranking is based on annualized total return for the 1-year, 3-year, 5-year and 10-year periods. Calamos Global Equity Fund Class I Shares were in the 49th, 5th, 37th and 52nd percentiles of 359, 305, 266 and 177 funds for the 1-year, 3-year, 5-year and 10-year periods, respectively, for the Morningstar Global Large-Stock category.

Calamos Global Equity Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

How is the Fund positioned?

The Fund is positioned with a combination of secular growth, cyclicals, commodities exposure, reopening opportunities and select defensives. Information technology, health care, industrials, financials, and consumer discretionary constitute the largest sector weights in the Fund. We hold key industry positions in pharmaceuticals, diversified banks, construction & engineering, aerospace & defense, software, and oil & gas. In addition, we own a range of holdings in energy and materials spanning companies we believe are positioned to benefit from supply-and-demand dynamics and attractive capital efficiency. We maintain an underweight stance in more defensive areas, including utilities, real estate, consumer staples and traditional telecoms.

From a geographic perspective, we own names within secular growth, cyclicals, and commodity businesses in the United States that prioritize earnings growth and advantaged business models. We own diversified holdings in Europe with a blend of end markets and business types. Our positioning largely consists of higher-quality global businesses that sustain strong balance sheets and demonstrate little reliance on demand in Europe. We have a modest weight in Japan, and we own multiple companies with attractive business models and relative earnings momentum. We own positions in emerging markets within key demand areas such as interactive media, apparel, and high-quality financials.

What closing thoughts do you have for Fund shareholders?

Global stocks continue to confront a set of complex crosscurrents. We are analyzing many aspects of economic activity alongside evolving policy actions, corporate earnings, and geopolitical factors. With persistent global inflation and tighter monetary policy, financial markets remain uncertain, and we expect global volatility will continue until these risks resolve. Within this complicated environment, we seek to identify ways to capitalize on volatility, including various opportunities at the thematic, regional and market-cap levels.

In terms of Fund positioning, we emphasize companies with favorable pricing power, strong earnings momentum, quality balance sheets and attractive valuations. From a sector perspective, we see opportunities in technology, industrials, health care, financials, energy and consumer discretionary with compelling fundamentals. We believe that our active investment approach and long-term perspective position us to take advantage of the volatility and opportunities in global markets.

Calamos Global Equity Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (3/1/07) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A, Class C and Class R6 shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Global Equity Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.58%, Class C shares is 2.33%, Class I shares is 1.33% and Class R6 shares 1.27%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.40%, 2.15%, and 1.15% of average net assets, respectively. The Fund's investment advisor has contractually agreed to limit the Fund's annual ordinary operating expenses for Class R6 shares (as a percentage of average net assets) to 1.15% less the annual sub-transfer agency ratio for the Fund. The annual sub-transfer agency ratio is equal to the aggregate sub-transfer agency expenses common to the other share classes of the Fund divided by the aggregate average annual net assets of the Fund's other share classes. For purposes of this expense limitation, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graph does not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

Calamos Global Equity Fund   (Unaudited)

The MSCI World Index (USD) is a free float-adjusted market-capitalization-weighted index composed of companies representative of the market structure of developed market countries in North America, Europe and the Asia/Pacific region.

The MSCI ACWI (USD) Index is a free float-adjusted market-capitalization-weighted index that is designed to measure the equity market performance of companies in developed and emerging markets. The MSCI ACWI (USD) Index is provided to show how the Fund's performance compares with the returns of an index of securities similar to those in which the Fund invests.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Global Opportunities Fund   (Unaudited)

OVERVIEW

The Fund invests primarily in global equity and convertible securities with an aim to balance risk/reward while providing growth and income.

KEY FEATURES

^◼  Combines equity and convertible holdings in order to limit downside risk while potentially capturing upside equity participation.

^◼  Provides a core holding option that strives to maintain a consistent risk posture throughout the market cycle.

^◼  Seeks to participate in the upside movements of the global equity market while lessening the impact of down periods.

PORTFOLIO FIT

The Fund can provide a long-term core allocation to global equities with the potential for lower volatility over full market cycles.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS GLOBAL OPPORTUNITIES FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12-months ended October 31, 2022 ("annual period"), Calamos Global Opportunities Fund returned -23.66% (Class I shares at net asset value), versus the MSCI ACWI Index's -19.58% return and MSCI World Index's -18.09% decline.

We believe the Fund's compelling medium and long-term performance record demonstrates its ability to generate excess returns over complete market cycles and varied investment environments. Since its inception on September 18, 1997, the Fund has returned 6.99% on an annualized basis (Class I shares at net asset value), compared to the 6.09% return of the MSCI ACWI Index and 6.34% return of the MSCI World Index. We manage the Fund with the goal of achieving upside equity participation and potential downside risk mitigation over full market cycles. We believe these figures demonstrate the Fund's ability to generate attractive long-term returns while pursuing a risk-managed investment approach.

What factors influenced performance during the annual period?

Global stocks struggled over the 12-month period amid a backdrop of persistently high inflation, rising interest rates, and heightened geopolitical tension. Looking forward, investors and companies have lowered their expectations in response to potential risks related to interest rates, high commodity costs and slowing demand fundamentals.

Pursuant to our risk-managed equity strategy, the Global Opportunities Fund navigated volatile markets while employing an active blend of common stocks, convertibles, and options. The Fund's performance over the period reflected the widespread declines across each of these asset classes. The Fund's relative return also trailed due to individual security selection. Our holdings in global companies with cyclical and secular growth characteristics trailed the more defensive and value-oriented market areas that held up relatively better amid the broad sell-off across markets.

The Fund's average overweight stance and favorable security selection in energy helped buoy relative returns. In particular, our holdings in the integrated oil & gas and oil & gas exploration & production industries supported relative results. Leading security selection in consumer discretionary added to the Fund's performance. The main contributors within this sector were automobile manufacturers and internet & direct marketing retail.

Over the annual period, selection within the information technology sector, primarily holdings in the semiconductors and data processing & outsourced services industries, dampened return. Security selection and an average underweight stance within the diversified banks and property & casualty insurance industries of the financials sector lagged on a relative basis.

Calamos Global Opportunities Fund   (Unaudited)

From a regional standpoint, our leading security selection in Canada contributed to performance. Our security selection and an underweight stance in EMEA also bolstered return. In particular, our lack of exposure to Russia contributed to relative performance. In contrast, selection in Emerging Asia hampered relative results, given that growth-oriented names underperformed the benchmark. In addition, security selection and an overweight allocation in Europe detracted from results in the period.

How is the Fund positioned?

In terms of Fund positioning, we emphasize companies with favorable pricing power, stronger earnings momentum, quality balance sheets, and attractive valuations. From a sector perspective, we see opportunities in technology, industrials, health care, financials, energy, and consumer discretionary companies with compelling fundamentals.

^◼  We have positioned the Fund with a combination of secular growth, cyclicals and commodities exposures, recovery opportunities, and select defensives.

^◼  Information technology, health care and industrials constitute the largest sector weights in the Fund. Key industry positions include pharmaceuticals, diversified banks, software, semiconductors, aerospace & defense, and oil & gas.

^◼  We own a range of holdings in energy and materials, spanning companies positioned to benefit from favorable supply and demand dynamics and attractive capital efficiency.

^◼  We maintain an underweight stance in certain defensive areas, including utilities, real estate, and more traditional telecoms.

^◼  Through a geographic lens, we own secular growth, cyclical and commodity businesses in the United States, which reflects our earnings growth, pricing power, and relative valuation.

^◼  We own diverse holdings in Europe with a blend of end markets and business types. Positioning largely consists of high-quality global businesses that sustain strong balance sheets and demonstrate less reliance on demand in Europe.

^◼  We have modest weight in Japan. We own multiple companies with better earnings momentum and more attractive business models.

^◼  We own positions in emerging markets within key demand areas such as interactive media, retail, semiconductors, and higher-quality financials.

What are your closing thoughts for Fund shareholders?

Global markets continue to confront a set of complex crosscurrents. We are analyzing many aspects of economic activity alongside evolving policy actions, corporate earnings, and geopolitical factors. With persistent global inflation and tighter monetary policy, financial markets remain uncertain, and we expect global volatility will continue until these risks resolve. Within this complicated environment, we seek to identify ways to capitalize on volatility, including a range of opportunities at the thematic, regional, and market cap levels. We believe that our active, risk-managed investment approach and long-term perspective positions us to take advantage of the volatility and opportunities in global markets.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Global Opportunities Fund   (Unaudited)

ANNUALIZED RETURN: SINCE INCEPTION (9/18/97) THROUGH 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted.

The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. You can obtain performance data current to the most recent month end by visiting www.calamos.com. Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average. All performance shown assumes reinvestment of dividends and capital gains distributions. Performance is for the Fund's Class I shares at net asset value. The Fund also offers Class A and Class C shares, the performance of which may vary. Source: State Street Corporation and Morningstar Direct.

*  Annual returns for Class I shares are provided because Class I shares represent the largest percentage of assets in the Calamos Family of Funds.

Calamos Global Opportunities Fund   (Unaudited)

GROWTH OF $1,000,000: FOR THE 10-YEAR PERIOD ENDED 10/31/22

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 1.45%, Class C shares is 2.20% and Class I shares is 1.20%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2023 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.22%, 1.97%, and 0.97% of average net assets, respectively. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The graphs do not reflect the income taxes that you would pay on fund distributions or the redemption of fund shares. Fund performance includes reinvestment of dividends and adjustment for the maximum sales charge for Class A shares. The performance of other classes will vary from the performance of the class shown based on the difference in sales charges and fees paid by shareholders investing in different share classes.

The MSCI ACWI Index is a free float-adjusted market-capitalization-weighted index that is designed to measure the equity market performance of developed and emerging markets.

The MSCI World Index (US Dollars) is a market-capitalization-weighted index composed of companies representative of the market structure of developed market countries in North America, Europe and the Asia/Pacific region. Since inception data for the index is shown from 9/30/97 since data is only available for full monthly periods.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos International Small Cap Growth Fund   (Unaudited)

OVERVIEW

The Fund seeks long-term capital appreciation by investing in compelling international small capitalization companies with superior earnings growth potential coupled with financial strength and flexibility.

KEY FEATURES

^◼  Provides access to an expansive opportunity set of small cap investments outside the United States, including businesses in emerging and frontier markets.

^◼  Our long-tenured Investment team has experience managing portfolios across multiple market cycles.

PORTFOLIO FIT

The Fund can provide an attractive asset-allocation building block often under-represented in US investors' portfolios. By diversifying into this less correlated asset class, investors may be able to offset declines in the overall market and reduce their portfolio's volatility with the potential for significant equity upside.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

CALAMOS INTERNATIONAL SMALL CAP GROWTH FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

The recently launched Calamos International Small Cap Growth Fund (CSGIX) provides investors exposure to an asset class often underrepresented in portfolios with the potential for diversification and alpha opportunities. Since its inception on March 31, 2022, the Fund has returned -23.40% (Class I shares at net asset value) versus the -21.99% return of the MSCI ACWI ex USA Small Cap Index (Net).

What factors influenced performance during the annual period?

International stocks faced a challenging environment over the period amid a backdrop of persistent higher inflation, rising interest rates, a strong dollar, and geopolitical tension. Looking forward, investors and companies have lowered expectations in response to potential risks related to interest rates, high commodity costs, and slowing demand fundamentals.

The Fund trailed the index over the period due to trailing relative security selection. Our holdings in small- to mid-capitalization companies with secular and cyclical growth characteristics trailed the more defensive and value-oriented market areas that held up relatively better amid the broad international equity selloff.

Introduction to the Fund

The recently launched Calamos International Small Cap Growth Fund (CSGIX) provides investors the following potential benefits:

^◼  Meaningful diversification. International small-cap stocks are less correlated to the US large- and small-cap markets, which we believe makes them excellent candidates for diversifying a portfolio. Non-US small caps are tied more closely to their local economy, serve different customers, and operate in different macroeconomic environments, thereby providing a different source of earnings. The Fund seeks investments in companies with superior earnings growth potential coupled with financial strength and flexibility.

^◼  The potential to add alpha. The international small-cap universe has the greatest number of stocks and fewest analysts per stock. This relative lack of coverage creates an opportunity for the Calamos team to uncover misunderstood or less followed companies, recognizing potential catalysts in advance of the broader market.

^◼  Access to an experienced investment team. The Fund builds on the team's historical success in identifying high-potential companies within key secular themes such as mobility and connectivity; mass digitization; artificial intelligence and automation; global demographic shifts; and advances in nanotech, biotech, and genetics, to name a few.

Calamos International Small Cap Growth Fund   (Unaudited)

What closing thoughts do you have for Fund shareholders?

International stocks continue to confront a set of complex crosscurrents. We are analyzing many aspects of economic activity alongside evolving policy actions, corporate earnings, and geopolitical factors. With persistent global inflation and tighter monetary policy, the financial markets remain uncertain, and we expect global volatility will continue until these risks resolve. Against this complicated backdrop, we seek to identify ways to capitalize on volatility, including a range of opportunities at the thematic, regional and market-cap levels.

In terms of fund positioning, we are emphasizing companies with strong earnings momentum, pricing power, flexible balance sheets, and attractive valuations. From a sector perspective, we see opportunities for compelling fundamentals in industrials, consumer discretionary, technology, health care, and energy. We believe that our active investment approach positions us to take advantage of volatility and opportunities in international small caps.

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos International Small Cap Growth Fund   (Unaudited)

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/30/22, the Fund's gross expense ratio for Class A shares is 2.07%, Class C shares is 2.82%, Class I shares is 1.82% and Class R6 shares is 1.71%. The Fund's investment advisor has contractually agreed to reimburse Fund expenses through March 31, 2025 to the extent necessary so that Total Annual Fund Operating Expenses of Class A shares, Class C shares and Class I shares are limited to 1.35%, 2.10% and 1.10% of average net assets, respectively. The Fund's investment advisor has contractually agreed to limit the Fund's annual ordinary operating expenses through March 31, 2025 for Class R6 shares (as a percentage of average net assets) to 1.10% less the Fund's annual sub-transfer agency ratio (the aggregate sub-transfer agency fees of the Fund's other share classes divided by the aggregate average annual net assets of the Fund's other share classes). For purposes of these expense limitations, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors LLC ("Calamos Advisors") may recapture previously waived expense amounts within the same fiscal year for any day where the respective share class's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

NOTES:

The benchmark MSCI ACWI ex USA Small Cap Index captures small cap representation across 22 of 23 Developed Markets (DM) countries (excluding the US) and 25 Emerging Markets (EM) countries.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Global Sustainable Equities Fund   (Unaudited)

CALAMOS GLOBAL SUSTAINABLE EQUITIES FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the period from Fund inception on December 17, 2021, through October 31, 2022, Calamos Global Sustainable Equities Fund returned -24.40% (Class I shares at net asset value) in line with the MSCI All Country World Index (ACWI) Net return of -21.14%.

What factors influenced performance over the annual period?

During the annual period, equity markets were overwhelmed with a steady diet of concerning news. Perhaps the biggest source of worry was the US Federal Reserve (the Fed) and the path it might take to tame inflation. Prior to the start of this annual period, the Fed had increased its inflation forecasts, raising the level of concern for market participants.

In February 2022, Russia invaded Ukraine, further adding to macroeconomic distress, in addition to the human tragedies associated with the conflict. The war disrupted many facets of life, but most notably from an economic perspective, it led to reductions in energy and food supplies, further adding to global inflation woes. The Fed began interest rate hikes on March 17, 2022, and by the end of the annual period, it had raised rates five times for a total of 300 basis points while pointing to additional aggressive hikes still to come. Globally, interest rates have likewise climbed, tightening financial conditions.

Global equity markets sold off throughout the annual period as market sentiment declined with concerns of stagflation—a combination of inflation and stagnant or negative economic growth, but the decline has been interrupted by several strong rallies, which offered hope the worst economic fears may have already been priced into the market. Adding to investors' woes, the bond market delivered difficult performance as evidenced by the higher-quality bond index, the Bloomberg US Aggregate Bond Index, registering a -15.68% return for the period.

Within the global equity market, the energy sector was the big winner with gains over 35% on global supply concerns. More defensively oriented areas such as health care, utilities and consumer staples fared well, though saw negative returns for the period. Growthier areas of the market, such as information technology, consumer discretionary and communication services, all lagged the market significantly.

The Fund's performance was most negatively affected by the absence of energy investments over the period. It's quite rare for the energy sector to display such outperformance over the entire market, besides the fact that the energy sector and its accompanying volatility is not suitable for our investment approach and mandate. In total, sector allocations were a net drag on relative performance, but sector allocations excluding energy were positive to relative performance,

OVERVIEW

The Fund seeks high-quality growth companies with strong environmental, social and governance (ESG) characteristics. Employing an integrated, fundamental and proprietary screening process, the Fund can invest in developed and developing economies across market capitalizations.

KEY FEATURES

^◼  Aims for above-average returns with lower volatility by focusing on companies that generate higher returns on capital, offer better growth prospects, and maintain a competitive edge.

^◼  Invests in companies with strong ESG characteristics, which we believe are better equipped to adapt to change while avoiding liabilities, thereby contributing to return potential and risk reduction.

^◼  Managed according to a time-tested proprietary process developed by our seasoned investment team, who established one of the first sustainable research platforms and helped set standards for ESG portfolios.

PORTFOLIO FIT

The Fund can serve as a global equity allocation for investors seeking above-average returns with potentially lower volatility from a portfolio of high-quality, ESG-principled companies offering enhanced prospects for growth.

FUND NASDAQ SYMBOLS

FUND CUSIP NUMBERS

Calamos Global Sustainable Equities Fund   (Unaudited)

SECTOR WEIGHTINGS

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

highlighted by our underweight to the underperforming communication services sector. At the individual issue selection level, the Fund was hurt by the market's strong bias to value-oriented and cheaper stocks, as opposed to our bias toward quality growth. Selection within health care lagged, notably in the health care equipment and pharmaceuticals industries. Fund holdings in industrials also trailed, largely within the electrical components & equipment industry.

How is the Fund positioned?

The portfolio remains broadly diversified and anticipates a low turnover in higher-quality businesses. It's our philosophy that companies with strong ESG characteristics are better equipped to adapt to change and to avoid unnecessary liabilities, thereby contributing to investor return potential and risk reduction—integrating ESG analysis with traditional financial analysis produces better financial and societal results. The Fund seeks to achieve above-average returns with lower volatility by focusing on companies that generate higher returns on capital, possess better growth prospects, and maintain sustainable competitive advantages over their peers. We believe a well-diversified portfolio of high-quality stocks can produce above-average market returns with lower volatility over the long term.

The fund maintained its overweight to western European markets, while holding an underweight to US holdings. As of the end of the period, the Fund's largest sector overweights reside in industrials and materials with energy and consumer staples comprising the largest underweights.

What closing thoughts do you have for Fund shareholders?

Inflation data continues to dominate the investing ecosystem. The stock market reflects the cost of inflation, and central banks are increasingly willing to pay for it at the expense of the economy. We believe we are closer to the end than the start of this tightening cycle, but the drainage of liquidity hasn't fully taken hold yet. As such, inflation and volatility are likely to stick around for a while longer.

We all know that the stock market isn't the economy, but it's a decent proxy for the growth outlook. Economists are slashing their growth forecasts while boosting inflation outlooks. Wall Street analysts are cutting earnings estimates as higher costs and rate pressures weigh on corporate margins. How should investors respond? How about concentrating on high-quality global leaders with strong balance sheets and environmental, social and governance (ESG) characteristics that can withstand tougher times. These global leaders will emerge from the downturn in a position of competitive strength with increased market share and shareholder returns.

We are fiduciaries seeking superior financial returns with less risk. ESG investing clearly aligns with this goal. ESG is not an asset class or an investment style. It is an enhancement to the investment process that provides a more holistic and complete view of risk and opportunity. ESG integration is the consideration of material nonfinancial factors, which are often unpriced externalities with long term risk-and-reward implications. We use this material nonfinancial information as we seek to make better investment decisions and build stronger portfolios.

Calamos Global Sustainable Equities Fund   (Unaudited)

It is our opinion that companies with strong ESG management and oversight are less likely to experience disruptions to their growth trajectory, cash flows, and earnings visibility. These are the primary drivers of stocks prices and valuation multiples. If companies don't manage their ESG risks and opportunities well, they won't keep up with their competitors. Firms that don't adapt to rising environmental constraints, changing consumer preferences, and societal shifts will face significant challenges. In addition, raising capital, attracting talent, and maintaining a positive brand image will be more difficult.

On October 31, 2022, the Board of Trustees approved a proposal to liquidate the Calamos Global Sustainable Equities Fund (the "Fund"). It is expected that the Fund will be liquidated in the first quarter of 2023. Additional information will be provided to shareholders regarding the timing of the liquidation, including the date on which the Fund will close to new investors and the date on which it will close to investments from current investors.

Calamos Global Sustainable Equities Fund   (Unaudited)

AVERAGE ANNUAL TOTAL RETURN^† AS OF 10/31/22

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost.

As of the prospectus dated 3/1/22, the Fund's gross expense ratio for Class A shares is 2.11%, Class C shares is 2.86%, Class I shares is 1.86% and Class R6 shares is 1.80%. The Fund's investment adviser has contractually agreed to reimburse Fund expenses through March 1, 2025 to the extent necessary so that Total Annual Fund Operating Expenses (excluding taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any) of Class A, Class C, and Class I are limited to 1.20%, 1.95%, and 0.95% of average net assets, respectively. The Fund's investment advisor has contractually agreed to limit the Fund's annual ordinary operating expenses for Class R6 shares (as a percentage of average net assets) to 0.95% less the annual sub-transfer agency ratio for the Fund. The annual sub-transfer agency ratio is equal to the aggregate sub-transfer agency expenses common to the other share classes of the Fund divided by the aggregate average annual net assets of the Fund's other share classes. For purposes of this expense limitation, operating expenses do not include taxes, interest, short interest, short dividend expenses, brokerage commissions, acquired fund fees and expenses, and extraordinary expenses, if any. Calamos Advisors may recapture previously waived expense amounts within the same fiscal year for any day where the respective Fund's expense ratio falls below the contractual expense limit up to the expense limit for that day. This undertaking is binding on Calamos Advisors and any of its successors and assigns. This agreement is not terminable by either party. The expense ratios shown above may differ from the more recent expense ratios reported in the Financial Highlights section of this report.

†  Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average assuming reinvestment of dividends and capital gains distributions. Performance shown reflects the effects of an expense reimbursement that improved results. Load-adjusted returns are adjusted for the maximum front-end sales load of 4.75% for Class A shares and returns for Class C shares have been adjusted for the contingent deferred sales charge (CDSC).

Calamos Global Sustainable Equities Fund   (Unaudited)

NOTES:

The MSCI ACWI Index (Net) is a free float-adjusted market-capitalization-weighted index that is designed to measure the equity market performance of developed markets and emerging markets. The index is calculated in both US dollars and local currencies. Net return basis approximates the minimum possible reinvestment of regular cash distributions by deducting withholding tax based on the maximum rate of the company's country of incorporation applicable to institutional investors.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

Calamos Total Return Bond Fund   (Unaudited)

OVERVIEW

Through its multi-sector fixed-income strategy, the Fund invests predominantly in US issuers with the goal of generating a high level of both current income and total return in excess of the benchmark over full market cycles.

KEY FEATURES

^◼  Employs bond-by-bond portfolio construction with a focus on being well compensated for risks taken. We believe a disciplined process, grounded in fundamental research, enables us to achieve higher total returns with less volatility.

^◼  Draws on a broader investable universe to enhance portfolio construction and risk management. The inclusion of high-yield bonds, bank loans and preferreds provides additional opportunities.

^◼  Utilizes robust, independent credit research. Our fixed-income investment process unites quantitative and qualitative analyses into historical and forward-looking models. The result is a credit rating reflective of where a company is heading.

^◼  Applies a macro overlay to capitalize on misunderstood industries and sectors. The overlay acts as a risk control that also considers the business cycle, geopolitical factors, inflation and real-rate expectations.

PORTFOLIO FIT

The Fund may be suitable as the cornerstone of a fixed-income allocation, with investments diversified across the major sectors of the US bond market. Allocations to specialized fixed-income strategies seek to enhance return potential and better manage risk.

FUND NASDAQ SYMBOLS

CALAMOS TOTAL RETURN BOND FUND

INVESTMENT TEAM DISCUSSION

How has the Fund performed?

For the 12 months ended October 31, 2022 ("annual period"), Calamos Total Return Bond Fund returned -14.92% (Class I shares at net asset value), outperforming the -15.68% return of the Bloomberg US Aggregate Bond Index and the -16.12% return of peers in the Morningstar Intermediate Core-Plus Bond Category.

Since its Class I shares inception on June 27, 2007, the Fund gained 2.87% on an annualized basis versus the 2.78% return for the Bloomberg US Aggregate Bond Index.

What factors influenced performance?

Economic and market conditions deteriorated rapidly during the second half of the annual period. Equity markets traded to all-time highs near the end of the 2021 calendar year as inexpensive capital and a pandemic-weary populace joined forces in lifting investment and spending across a variety of industries. By June, however, the S&P 500 Index entered bear market territory as rotating inflation and revised corporate earnings outlooks began taking hold.

From a nominal perspective, some areas such as retail sales and personal spending indicate that consumer activity is growing even as inflation related to food and energy has driven up the cost of essentials to uncomfortable highs. Meanwhile, purchasing manager indices related to services, calibrated to indicate growth when above 50, have not fallen below that critical level. In stark contrast, consumer confidence levels hover near all-time lows, primarily driven by gloomy expectations for the future. Further, the housing sector has slowed to a crawl. All this points to a significant deceleration in economic activity—and although time will tell whether this leads to a domestic or global recession, the risk of one is clearly increasing.

Calamos Total Return Bond Fund   (Unaudited)

Inflation measures have continued to reflect price increases across a wide range of goods and services. The Producer Price Index (PPI), a measure of the price change in goods as they leave their place of production, grew at greater than 8% annualized in September. PPI sometimes serves as a leading indicator for consumer prices because producers will pass along the higher cost of raw materials to consumers in future months. This only raises the level of concern as consumer prices continue to register near multi-decade highs.

The Federal Reserve (the Fed) has turned its focus entirely to fighting persistent inflation and anchoring its decision-making to long-term inflation expectations. A severe decoupling of inflation expectations from the Fed's stated target of 2% over time may lead to changes in consumer behavior and a greater likelihood of a price-wage spiral. Having already hiked its overnight interest rate from the zero-lower bound to a range of 3.75% to 4.00%, markets are anticipating five more 25-basis-point Fed hikes to take effect before midyear 2023. The actual amount of policy tightening from here will be largely driven by how the inflation environment unfolds in the coming months. In addition, quantitative tightening has officially begun, with the Fed allowing balance sheet holdings of Treasury and mortgage-backed securities to roll off as opposed to reinvesting proceeds.

Covid-19 is far from gone, but its influence on markets has waned as governments attempt to strike a balance between public health and economic normalcy. A lack of future fiscal stimulus will also translate to a deceleration in spending because Covid-era transfer payments are unlikely to reemerge.

Domestic equity markets delivered deeply negative returns across market capitalizations and styles. Historically, defensive sectors such as consumer nondiscretionary, utilities and health care have outperformed, whereas the consumer discretionary and technology sectors fared worse. The strongest performing sector across asset classes has been energy, which is unusual given the sector's unclear growth outlook. Energy's recent leadership likely reflects the strength of both the commodity complex and structural issues in the sector.

Corporate credit markets have exhibited less volatility than stocks indicate. After beginning the annual period near historic all-time tights, investment-grade spreads closed the period close to cycle wides of 158 basis points. The velocity of the move wider was strongest during the first calendar quarter of 2022 and has settled into a slower migration since, but the prevailing direction is consistent. Given the Fed's policy tightening and spread widening, there are now frequent opportunities to buy investment-grade bonds with 6% coupons, territory that would have been reserved for B-rated credits only a year ago. Issuance volumes dropped precipitously for several months, leading to a contraction in the size of the corporate debt market for the first time in over a decade during the third calendar quarter because borrowers are less eager to lock in funding at higher rates.

Entering the annual period, the Treasury curve did not have a single point on it above 2%, reflecting the effective lower-bound policy rate from the Federal Reserve and sanguine inflation expectations based on a general interpretation that price increases were transitory and limited to select areas of the economy affected by supply chain issues. In short order, however, Treasury yields moved substantially higher with short maturities inside of five years climbing by more than 3%, while long-dated maturities of 10 and 30 years rose by more than 2%. All this, coupled with the aforementioned spread widening across risk sectors, drove negative investor returns in core bond strategies. The government-related components of

FUND CUSIP NUMBERS

ASSET ALLOCATION

Asset Allocation weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Fund may hold.

Calamos Total Return Bond Fund   (Unaudited)

the Bloomberg US Aggregate Bond Index led sectors with a -13.5% return, Treasuries returned -14.1%, securitized products returned -14.8%, and corporate bonds returned -19.6%.

The Fund held an overweight allocation in corporate debt over the annual review period. Although the overweight position in industrial sector corporate debt detracted from performance, security selection among those same issuers significantly offset the allocation drag and contributed to performance. Security selection among the Fund's positions in the Treasury sector hindered returns, whereas selection among mortgage-backed securities was additive. The team materially decreased the corporate bond allocation during the year. Over the full market cycle, we continued to favor an overweight to corporate bonds and asset-backed securities in the Fund, given that the additional yield has historically generated superior long-term returns.

How is the Fund positioned?

The Fund has a duration of 5.9 years, short of the 6.1 year duration of the Bloomberg US Aggregate Bond Index.

The Fund continues to hold an overweight in corporate bonds in both the investment-grade and out-of-benchmark high yield ratings categories. These overweights led to a lower overall credit quality of A- when compared with the AA- quality of the benchmark. The rapid move higher in Treasury rates coupled with the widening of spreads in risk assets led to negative returns during the annual period—though the Fund finished ahead of both the Bloomberg US Aggregate Bond Index and the Morningstar Intermediate Core-Plus Bond Category peer group average. The Fund continues to hold overweight positions in corporate and asset-backed securities and underweight positions in Treasuries and mortgages following the year's activity. Within corporate bonds, our largest overweight allocations are in the transportation and consumer non-cyclical sectors.

What are your closing thoughts for Fund shareholders?

Risk premia are back, and investors are demanding a higher level of compensation for any level of assumed risk across asset classes and securities. This includes higher requirements for equity investments in the form of lower multiples, higher spread compensation for credit risk, and higher term premia for duration risks. Some of these shifts were bound to happen with the Fed unwinding years of extraordinarily easy monetary policy as we emerge from the Covid-19 pandemic. These shifts are related to an outlook for weaker growth and employment data to follow on the heels of persistent, generationally high inflation. We expect the uncertainty and the associated higher levels of compensation to endure.

The probability of left-tail risk (for example, a recession, supply chain issues, return to Covid-19 lockdowns) is also increasing along with the median expectation for growth moving materially lower. This has led to a risk-off environment with lower asset prices. We believe that some of the Fed's activity has transmitted to the real economy as monetary policy moves through financial markets near the short end of its historical 6- to 18-month range. In addition, market reactions ahead of the widely anticipated Fed policy "catch-up" are tightening financial conditions, particularly via higher mortgage rates.

Inflation is rotating away from goods and toward services as more consumer dollars are spent on experiences outside the home post-pandemic, including travel. From our perspective, this is a negative development because goods are largely produced outside the United States, whereas services are almost entirely produced

Calamos Total Return Bond Fund   (Unaudited)

and consumed domestically, leading to a greater likelihood of a price-wage spiral. In addition, the massive moves higher in shelter components of the consumer price index will continue to play out over the coming quarters as those measurements are gradually included in the calculation. The Fed's inflation fight will likely be longer and more difficult than most market participants are acknowledging. Elevated volatility, which is being stirred up by a wide range of potential outcomes, is likely here to stay.

Given that economic growth at the aggregate level is all about marginal activity, we also expect real economic growth to roll over much more quickly and prominently than broad market expectations. Many individuals in the bottom income quartile have exhausted pandemic savings and are faced with costs of essentials that are hundreds of dollars a month higher than they were a year ago. Although a technical recession may be avoided, this level of deterioration in economic activity will feel like a recession to many Americans.

The broad market outlook appears to be migrating closer to the reality depicted in economic data. We expect additional data deterioration as the Fed accepts weaker employment conditions to defeat inflation before it becomes further entrenched in consumer expectations. Even so, yields have increased significantly, and fixed income securities now offer investors a return for taking risks. In addition, quality assets should provide more of their traditional safe haven status if our bear case does occur.

ANNUALIZED RETURN: SINCE INCEPTION (6/27/07) THROUGH 10/31/22