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

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number: 811-22099

Gateway Trust

(Exact name of Registrant as specified in charter)

888 Boylston Street, Suite 800 Boston, Massachusetts 02199-8197

(Address of principal executive offices) (Zip code)

Natalie Wagner, Esq.

Natixis Distribution, LLC

888 Boylston Street, Suite 800

Boston, Massachusetts 02199-8197

(Name and address of agent for service)

Registrant’s telephone number, including area code: (617) 449-2810

Date of fiscal year end: December 31

Date of reporting period: December 31, 2021

Item 1. Reports to Stockholders.

Annual Report

December 31, 2021

Gateway Fund

Gateway Equity Call Premium Fund

Mirova Global Green Bond Fund

Mirova Global Sustainable Equity Fund

Mirova International Sustainable Equity Fund

Mirova U.S. Sustainable Equity Fund

Table of Contents

GATEWAY FUND

Investment Goal

The Fund seeks to capture the majority of returns associated with equity market investments, while exposing investors to less risk than other equity investments.

Management Discussion

2021 was the third consecutive year of double-digit return for the S&P 500^® Index, powering its three-year cumulative return above 100% for the first time since early March 2012, a three-year period that began at the bear market bottom of the Great Financial Crisis. Additionally, returns were positive in each quarter of 2021, though the September equity market pullback brought that streak to the brink. The equity market started the year in impressive fashion with returns of 6.17% and 8.55% in the first and second quarters, respectively. Macroeconomic stabilization and improvement driven by a relaxation of pandemic mitigation policies and additional fiscal stimulus helped investors digest concerns surrounding the outlook for inflation, labor market imbalances, and rising interest rates. Equity market strength continued in July and August, but the S&P 500^® Index eked out a third quarter return of just 0.58% as the market pulled back, surrendering to a growing list of investor concerns including new Covid-19 variants, the outlook for inflation and uncertainty surrounding fiscal and monetary policy. September’s decline carried into early October as the S&P 500^® Index lost 5.12% from September 2 to October 4, its largest peak-to-trough drawdown of the year. The equity market’s fourth quarter was the strongest of all, with a return of 11.03%, but was not the smoothest as inflation and monetary policy concerns drove a short but intense bout of volatility mid-quarter. The S&P 500^® Index ended the year just shy of its all-time high reached on December 29.

The downtrend in implied volatility that began after the Cboe^® Volatility Index (the VIX^®) peaked at record levels in March 2020 continued over the first half of 2021. The VIX^® spent most of the year ranging from the mid-teens to the low 20s while posting 21 days of closing values above 25, including six days when it closed above 30. The result was an average closing value of 19.66 for the year, slightly above its long-term average of 19.48. While the downtrend brought the measure to below-average levels at various points throughout the year, it never closed below 15, thus establishing a Covid-19 era low that was above the low readings that persisted for several years prior to the pandemic. Specifically, the VIX^® averaged 14.86 during the seven-year period from 2013 to 2019. Although implied volatility was elevated in 2021, realized volatility, as measured by the standard deviation of daily returns for the S&P 500^® Index, was below-average at 13.09% for the year. The spread between S&P 500^® Index realized volatility and average implied volatility, often referred to as the Volatility Risk Premium (VRP), was positive in 2021, as is typical. However, the spread was consistently wider than normal as VRP ended the year on a 15-month trend of readings that have been above the historical monthly average of 4.15%.

Performance Results

For the 12 months ended December 31, 2021, Class Y shares of the Gateway Fund returned 11.49% at net asset value. The Fund’s primary benchmark, the S&P 500^® Index, returned 28.71% for the same period, while its secondary benchmark, the Bloomberg U.S. Aggregate Bond Index, returned -1.54%.

Explanation of Fund Performance

The Fund invests in a broadly diversified portfolio of common stocks that is designed to track the performance of the S&P 500^® Index, while also selling index call options and purchasing index put options. The Fund seeks to generate returns by creating cash flow through writing at-the-money index call options against the full value of its underlying equity portfolio. The written call options, premium levels of which have a high correlation to volatility, provide cash flow into the Fund, yet may limit upside participation in an equity market advance. The Fund uses some of the cash flow from index call option writing to purchase out-of-the-money index put options to mitigate sudden and severe price declines in the equity portfolio. An index call option is considered at-the-money when the price of the underlying index is the same as the option’s strike price. Additionally, an index put option is deemed out-of-the money when its strike price is below the price of the underlying index. It is the net premium-to-earn from selling index call options less the price of protective index put options that is a significant factor in determining how much participation the Fund will have in a rising

1  |

market and how much downside mitigation is delivered in a declining market. In the long term, the combination of the diversified stock portfolio, steady cash flow from the sale of index call options and downside mitigation from index put options is intended to provide the Fund with a majority of the returns associated with equity market investments while exposing investors to less risk.

The Fund underperformed its primary benchmark for the year while achieving the risk component of its objective by exhibiting less than half the risk of the equity market. 2021 marked the Fund’s highest calendar year return since 2003. Returns for the year were buoyed by relatively elevated implied volatility and active management focused on the higher volatility priced into longer-dated call option contracts and a persistently above-average VRP. The Fund’s two-part option strategy delivered significant risk mitigation during market declines and equity market participation during the periods in which the equity market advanced. Specifically, the Fund had smaller losses than the S&P 500^® Index when equity market returns were negative in January, September and November and provided 2.51 percentage points of risk mitigation with a return of -2.61% during the max drawdown period for the S&P 500^® Index from September 2 through October 4. The Fund’s positive but lagging returns of 3.23%, 3.98% and 4.32% in the first, second and fourth quarters of 2021 led to underperformance for the year as the Fund was unable to keep pace with the S&P 500^® Index’s strong advances. When the equity market advances at an above-average rate, underperformance is expected, as the risk-reducing option strategy generates losses that detract from return. Consequently, the fourth quarter, which was the strongest equity market quarter of the year, produced the most significant period of lagging performance for the Fund. From October 4 through November 18, the equity market’s recovery from its largest loss of the year developed into a rally to new highs and the S&P 500^® Index advanced 9.60%, while the Fund generated a return of 4.06%. Over the remainder of the year, the S&P 500^® Index added 1.47% to its return while the Fund returned 0.43%.

The Fund’s equity portfolio returned 28.38% in 2021, a performance differential of (0.33) percentage points versus the S&P 500^® Index. Consistent with its investment objective, the measured risk of the Fund was low relative to the US equity market, as its standard deviation of daily returns for 2021 was 6.12% versus 13.09% for the S&P 500^® Index.

The Fund began the year with index put option coverage in a range of 80% to 95%, a positioning that had been maintained since August 2020. The investment team incrementally added index put options in January, restoring put coverage to greater than 95% by the end of the month. The increases in put coverage in January were executed in conjunction with adjustments to the Fund’s written call option positions with the goal of maintaining a consistent risk profile while benefiting from lower put costs. Amid heightened equity market volatility in late November and early December, Gateway’s investment team opportunistically monetized higher volatility being priced into index put contracts and preserved index put gains in the event of a sudden and sharp market recovery, while maintaining the Fund’s typical risk profile. The investment team closed out one index put option position on December 3, lowering put coverage to a range of 80% to 95%. This position was maintained until December 16 when the investment team restored put coverage to greater than 95% as index put options became more reasonably priced when VIX^® levels declined from their relatively elevated levels earlier in the month. The Fund maintained a portfolio of written index call options on the full value of its equity holdings over the course of the year, while making active adjustments to positions in response to changing market conditions and opportunistically taking advantage of the higher implied volatility that was priced into longer-dated contracts.

Outlook

Gateway’s investment philosophy is informed by its long history and maintains that the equity market is the most reliable source of attractive long-term returns, despite its high volatility relative to other asset classes and tendency to periodically deliver significant short-term losses. Gateway’s investment philosophy also holds that consistency is key to long-term success and that generating cash flow with index options, rather than seeking to forecast the market, can lower the risk of participating in equity markets. By staying true to this philosophy and continuing to manage strategies consistent with the firm’s historical approach, Gateway assists Fund shareholders in managing risk while pursuing long-term returns in an uncertain environment. Rather than attempting to anticipate how events will unfold, Gateway will continue to focus on making prudent adjustments to its option portfolios to maintain the risk profile of the Fund in response to changing market conditions.

|  2

GATEWAY FUND

Hypothetical Growth of $100,000 Investment in Class Y Shares⁴

December 31, 2011 through December 31, 2021

Top Ten Holdings as of December 31, 2021

The portfolio is actively managed and holdings are subject to change. There is no guarantee the Fund continues to invest in the securities referenced. The holdings listed exclude any temporary cash investments, are presented on an individual security basis and do not represent holdings of the issuer.

3  |

Average Annual Total Returns – December 31, 2021⁴

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For more recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

|  4

GATEWAY EQUITY CALL PREMIUM FUND

Investment Goal

The Fund seeks total return with less risk than U.S. equity markets.

Management Discussion

2021 was the third consecutive year of double-digit return for the S&P 500^® Index, powering its three-year cumulative return above 100% for the first time since early March 2012, a three-year period that began at the bear market bottom of the Great Financial Crisis. Additionally, returns were positive in each quarter of 2021, though the September equity market pullback brought that streak to the brink. The equity market started the year in impressive fashion with returns of 6.17% and 8.55% in the first and second quarters, respectively. Macroeconomic stabilization and improvement driven by a relaxation of pandemic mitigation policies and additional fiscal stimulus helped investors digest concerns surrounding the outlook for inflation, labor market imbalances, and rising interest rates. Equity market strength continued in July and August, but the S&P 500^® Index eked out a third quarter return of just 0.58% as the market pulled back, surrendering to a growing list of investor concerns including new Covid-19 variants, the outlook for inflation and uncertainty surrounding fiscal and monetary policy. September’s decline carried into early October as the S&P 500^® Index lost 5.12% from September 2 to October 4, its largest peak-to-trough drawdown of the year. The equity market’s fourth quarter was the strongest of all, with a return of 11.03%, but was not the smoothest as inflation and monetary policy concerns drove a short but intense bout of volatility mid-quarter. The S&P 500^® Index ended the year just shy of its all-time high reached on December 29.

The downtrend in implied volatility that began after the Cboe^® Volatility Index (the VIX^®) peaked at record levels in March 2020 continued over the first half of 2021. The VIX^® spent most of the year ranging from the mid-teens to the low 20s while posting 21 days of closing values above 25, including 6 days when it closed above 30. The result was an average closing value of 19.66 for the year, slightly above its long-term average of 19.48. While the downtrend brought the measure to below-average levels at various points throughout the year, it never closed below 15, thus establishing a Covid-19 era low that was above the low readings that persisted for several years prior to the pandemic. Specifically, the VIX^® averaged 14.86 during the seven-year period from 2013 to 2019. Although implied volatility was elevated in 2021, realized volatility, as measured by the standard deviation of daily returns for the S&P 500^® Index, was below-average at 13.09% for the year. The spread between S&P 500^® Index realized volatility and average implied volatility, often referred to as the Volatility Risk Premium (VRP), was positive in 2021, as is typical. However, the spread was consistently wider than normal as VRP ended the year on a 15-month trend of readings that have been above the historical monthly average of 4.15%.

Performance Results

For the 12 months ended December 31, 2021, Class Y shares of the Gateway Equity Call Premium Fund returned 19.43% at net asset value. The Fund underperformed its primary benchmark, the Cboe S&P 500 BuyWrite Index (BXM^SM), which returned 20.47% for the period. The Fund also underperformed its secondary benchmark, the S&P 500® Index, returned 28.71%.

Explanation of Fund Performance

The Fund invests in a broadly diversified portfolio of common stocks that is designed to track the performance of the S&P 500^® Index and support its index option-based risk management strategy as efficiently as possible while seeking to enhance the Fund’s after-tax total return. The Fund seeks to generate returns by writing at- and near-the-money index call options against the full value of its underlying equity portfolio. The steady cash flow from call option writing is intended to be an important source of the Fund’s return, although it reduces the Fund’s ability to profit from increases in the value of its equity portfolio. The index call options written by the Fund often have similar characteristics to the single index call option present in the BXM^SM at any given time. However, unlike the BXM^SM, the Fund employs an active strategy that gives its management team discretion to diversify expiration dates and strike prices across a portfolio of index call options and to opportunistically pursue attractive call premiums while maintaining a relatively consistent risk profile.

The Fund underperformed its primary benchmark for the year while achieving the risk component of its objective by exhibiting less risk than the equity market. 2021 marked the Fund’s highest calendar-year return since its inception in 2014. Returns for the year were buoyed by relatively elevated implied volatility and active management focused on the higher volatility priced into longer-dated call option contracts and a persistently above-average VRP. The Fund’s diversified and active index call option writing approach

5  |

generated risk reducing cash flow throughout 2021 while delivering equity market participation during periods in which the equity market advanced and downside risk mitigation during market declines. Specifically, the Fund produced positive returns in all four quarters while incurring smaller losses than the S&P 500^® Index in January, September, and November when equity market returns were negative. Furthermore, the Fund provided loss mitigation of 2.28 percentage points during the maximum drawdown period for the S&P 500^® Index with a return of -2.84% from September 2 through October 4. After outperforming the BXM^{SM in the first half of the year with a return of 11.41% compared to the BXM’sSM return of 11.10%, the Fund underperformed in the second half with a return of 7.20%, compared to the BXM’sSM return of 8.43%. This was due primarily to the Fund’s performance during the equity market’s recovery and rally to new highs after its brief but sharp decline from late November to early December. As the equity market began to recover, the BXMSM was better positioned for a market advance, having more market exposure than usual because the index call option it wrote in November was far out-of-the-money after the equity market decline. The Fund, in contrast, had less market exposure than the BXMSM because its actively managed approach lowered the weighted-average strike price of its written call option portfolio as the market declined in order to maintain its typical risk profile. Consequently, as the market advanced over the remainder of December, the BXMSM returned 4.86%, while the Fund returned 3.64%, underperforming by 1.22%. Prior to December’s equity market advance, the Fund had outperformed the BXMSM in 2021, as its year-to-date return through December 1 was 15.23% compared to 14.89% for the BXMSM. .}

The Fund’s equity portfolio returned 28.87% for the year, a performance differential of positive 0.16 percentage points versus the S&P 500^® Index. The measured risk of the Fund was lower than that of the US equity market and the BXM^SM, as its standard deviation of daily returns for 2021 was 8.50%, versus 13.09% and 8.61% for the S&P 500^® Index and the BXM^SM, respectively.

Outlook

Gateway’s investment philosophy is informed by its long history and maintains that the equity market is the most reliable source of attractive long-term returns, despite its high volatility relative to other asset classes and tendency to periodically deliver significant short-term losses. Gateway’s investment philosophy also holds that consistency is key to long-term success and that generating cash flow with index options, rather than seeking to forecast the market, can lower the risk of participating in equity markets. By staying true to this philosophy and continuing to manage strategies consistent with the firm’s historical approach, Gateway assists Fund shareholders in managing risk while pursuing long-term returns in an uncertain environment. Rather than attempting to anticipate how events will unfold, Gateway will continue to focus on making prudent adjustments to its option portfolios to maintain the risk profile of the Fund in response to changing market conditions.

Hypothetical Growth of $100,000 Investment in Class Y Shares⁴

September 30, 2014 (inception) through December 31, 2021

See notes to chart on page 7.

|  6

GATEWAY EQUITY CALL PREMIUM FUND

Top Ten Holdings as of December 31, 2021

The portfolio is actively managed and holdings are subject to change. There is no guarantee the Fund continues to invest in the securities referenced. The holdings listed exclude any temporary cash investments, are presented on an individual security basis and do not represent holdings of the issuer.

Average Annual Total Returns – December 31, 2021⁴

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For most recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

7  |

MIROVA GLOBAL GREEN BOND FUND

Investment Goal

The Fund seeks to provide total return, through a combination of capital appreciation and current income, by investing in green bonds.

Market Conditions

In wake of 2020, we anticipated that 2021 would be i) far less impacted by the Covid-19 crisis and ii) marked by inflation blips as a result of a combination of central banks’ balance sheet expansion, production bottlenecks, and consumers’ willingness to spend the cash reserves they had accumulated over lockdowns and curfews. The Delta variant has derailed this scenario, except for inflation, which has driven rates far higher on the back of fears that central banks would little by little have to accept that surging prices could last longer than they were previously claiming. This is what has driven the German Bund from -0.60% to -0.18% and US 10-year rates from 0.90% to 1.50% over the year, with dramatic swings which were largely attributable to Delta. Credit markets rallied up to the end of November when the discovery of the Omicron variant ignited a wave of panic that quickly dissipated due to the variants’ lack of severity.

Performance Results

For the 12 months ended December 31, 2021, Class Y shares of the Mirova Global Green Bond Fund returned -2.69% at net asset value. The Fund underperformed its benchmark, the Bloomberg MSCI Green Bond Index – USD Hedged, which returned -2.30%.

Explanation of Fund Performance

The duration and curve strategy detracted from performance as the Fund’s global duration was set lower than the index during February on the long end of the curve when yields globally went down due to the Delta variant. Furthermore, the curve flattening had negative performance implications for the Fund.

From an allocation perspective, the Fund’s strategy was positive. The long position in corporates versus other asset classes paid off. Since the beginning of the year, we saw value in this asset class, which had full support from central banks. Credit exposure represented approximately 50% of the Fund during the year.

Security selection decisions brought value, mainly within the corporate sector. The main contributors were Baywa, Vena Energy and Orsted. Baywa is a German group specialized in energy, agriculture and building materials. Credit spreads on the Fund’s holdings contracted by 100 basis points (bps), due to their positive business, driving performance. Vena Energy is a utility company from Singapore, whose credit spreads on the Fund’s holdings contracted, due to the issuer’s high beta profile, resulting in positive contributions to overall returns., Orsted, which is one of the leaders in offshore wind turbines in Europe, benefited from spreads contracting.

Outlook

As Omicron is reportedly less aggressive than the Delta variant it is beginning to overcome, there is a decent probability that the Covid-19 crisis loses further traction, which may fuel even more positive momentum for the economy, especially for the lowest paid workers, provided central banks manage to curb inflation without jeopardizing the growth prospects we think are very solid. We believe central bankers will have the means to reach that target, which means 2022 might be constructive. The only real cloud on the horizon remains whether Russia’s Putin and the Western leaders might find an agreement to avoid prompting any kind of intervention of either NATO or Russia, if not both, in Ukraine.

|  8

MIROVA GLOBAL GREEN BOND FUND

Hypothetical Growth of $100,000 Investment in Class Y Shares²

February 28, 2017 (inception) through December 31, 2021

Average Annual Total Returns – December 31, 2021²

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For most recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

9  |

MIROVA GLOBAL SUSTAINABLE EQUITY FUND

Investment Goal

The Fund seeks long-term capital appreciation.

Market Conditions

2021 was generally a very positive year for global equity investors, albeit with high levels of volatility. Low interest rates and central bank support through bond buy-back programs provided an almost endless level of money supply for the economy and markets. This has pushed up valuations in equity markets, especially in high growth sectors and the US market in general. Inflation and concerns that this favorable low interest rate environment may soon end have led to a sector and style rotation during 2021. Traditional energy companies and banks benefited the most, also helped by higher oil prices and higher interest rates, respectively. Renewable energy stocks underperformed significantly, having entered the year with relatively high valuations. Increased competition from oil and gas companies, combined with supply chain issues (raw material price inflation and transportation issues), further impacted margins negatively in the wind sector, and less favorable proposed regulation in California adversely impacted solar companies. Growth stocks posted generally strong results, but we saw that many large technology stocks are also not immune to wage inflation and supply chain issues.

In the real world, natural disasters caused human and economic tragedies. Wildfires in southern Europe and California, floods in Germany, Austria and Belgium, and Hurricane Ida are major examples of this year’s climate change-related disasters, with a combined economic cost of well over $100 billion. Markets didn’t blink, at least not until September when it became clear that Chinese property developer China Evergrande, a group with $260 billion in debt, was in financial trouble; fears of another Lehman scenario led to a quick correction in equity prices globally. Elsewhere in the market, oil and gas prices continued their upward trajectory as demand increased while supply did not follow the same path, even causing some bankruptcies in the UK utility sector. A shortage of drivers in the transportation sector and a general lack of employees in other sectors created shortages and wage inflation. Nonetheless, earnings growth in developed markets was, on average, stronger than expected in 2021, pushing global equity markets to all-time highs in November. However, the year ended as it started, with high volatility as some economies found themselves again in lockdown because of concerns around the Omicron variant of the Covid-19 virus.

Performance Results

For the 12 months ended December 31, 2021, Class Y shares of the Mirova Global Sustainable Equity Fund returned 18.06% at net asset value. The Fund underperformed its benchmark, the MSCI World Index (Net), which returned 21.82%.

Explanation of Fund Performance

There were a few drivers of the strategy’s underperformance in 2021. The strategy focuses on investing in companies positively exposed to long-term secular trends, resulting in less cyclical exposure compared to the broad market. The strategy has no exposure to traditional energy and is underweight financials, particularly large banks as the team doesn’t see them as being positively exposed to secular trends. Energy and financials performed very strongly during the year, and the lack of exposure in these sectors hurt relative performance.

Alternative energy stocks Orsted and Vestas declined significantly during the year. Given a strong outlook for the long-term demand environment for renewable energy, particularly offshore wind, and with both stocks having sustainable competitive advantages, the team remains comfortable continuing to hold them. Although competition has increased, updated valuation analysis incorporating significantly increased competition in their markets shows both stocks are trading at significant discounts to intrinsic value.

Stock selection in Communication Services, coupled with a significant underweight to the sector, positively impacted performance. Additionally, stock selection within Health Care benefitted performance driven by continued strong performance from healthcare equipment providers ThermoFisher and Danaher, along with Novo Nordisk and Eli Lilly.

The portfolio invests in companies offering solutions to and/or expecting to benefit from the demographic, technological, environmental and governance-related transitions that are expected to transform the world’s economies and societies during the next decade.

|  10

MIROVA GLOBAL SUSTAINABLE EQUITY FUND

From a geographical standpoint, the portfolio is underweight the U.S. This regional allocation is driven by bottom-up valuation; the U.S. is on its 12^th year of outperforming international markets and the team continues to find better valued opportunities outside the U.S.

The portfolio continues to have a bias to European names while being underweight US names; this bias is a result of bottom-up fundamental analysis where the team is finding more attractively priced securities outside of the US, given US outperformance over international markets since 2011. In terms of sector exposure, the portfolio currently has no exposure to energy (oil and gas extraction) or real estate and is underweight financials. This is mainly driven by valuation (real estate) and the team’s thematic and sustainability approach as trends like the digitalization of our economy, which saw strong Covid-19-related growth, are expected to continue to grow strongly. Similarly, support for the health care sector is expected to show solid growth as a reaction to COVID-19 in the short-term, and as a result of an aging population and continued focus on health and well-being in the longer-term; as such, the portfolio remains overweight health care. There is also an underweight position in the more defensive consumer staples sector, which to some extent is offset by an overweight position in materials (mainly natural food ingredients). With many governments still committed to keeping global warming limited to a 2-degree Celsius scenario, we expect climate change to remain a driver of political debate, and the portfolio will continue to shy away from fossil fuel extraction in favor of renewables and companies focused on energy efficiency. The team continues to prefer companies with strong balance sheets, solid management teams, and positive exposure to long-term secular trends.

During the first quarter of 2021, the investment team trimmed several stocks where they did not see as much upside in valuation after strong stock runs including Signature Bank, Aptiv, Novo Nordisk, and Alphabet. The proceeds were used to add to Takeda, the Japanese pharmaceutical company, and technology company Adobe. We also initiated positions in Nvidia Corp. and Eli Lilly & Co.

In the second quarter, the investment team exited positions in Chr. Hansen Holding A/S, Coloplast, and Danone, and added to Bright Horizons and NVIDIA.

During the third quarter the team added to their position in AIA Group Ltd. AIA is the leader in the Asian life insurance market with business in more than 15 Asian countries. It is uniquely positioned to benefit from the structural long-term opportunities driven by higher population growth, stronger income growth and lower life insurance penetration in Asian countries. Its stock price was recently hurt, partly by new Delta variant concerns, and its valuation became more attractive, presenting a great opportunity for the investment team to add to the position.

Over the course of the fourth quarter, the team exited positions in both Alphabet Inc. and Eaton Corp., added new positions in Iberdola, MercadoLibre, Sunrun, and Xylem, while also trimming their position in Nvidia Corp., and adding to Ball Corp., Mastercard, Ecolab, Eli Lilly, and Oracle.

Outook

Covid-19 stimulus spending is expected to provide a robust platform for long-term economic growth, as many governments try to stimulate their local economies by targeting infrastructure investments. Areas like water infrastructure, sustainable and local energy production, health care, education and transport infrastructure cannot be outsourced to other low-cost countries, thus creating local jobs while offering the additional benefit of providing platforms for companies to innovate and grow. The Covid-19 crisis has also accelerated the transition toward a more digital economy. While many companies are facing high costs to deal with this transition, others are expected to benefit from it, especially solution providers in areas like cloud computing, e-retail, and fintech. Fintech could also be disruptive for traditional banking models, offering solutions for financial inclusion of the poorest of our population, particularly in emerging markets. Climate change awareness is high, especially after the natural disasters that have hit many parts of the world in the past several months. With November’s 2021 United Nations Climate Change Conference (COP 26), we would expect many governments and multinational companies to announce strong and increased targets for renewable energy production, with multiple opportunities for renewable and traditional energy players, as the latter are also increasing their footprint in the renewable energy and hydrogen space.

Even after the recent correction in equity markets, valuations still do not look cheap. Risks are visible at many levels which could create high volatility. A potential collapse of the Chinese property market and financial system could have serious ripple effects in the rest of the world. The Delta and Omicron variants of Covid-19 are very contagious and not enough people in developing countries are vaccinated yet, while in many emerging countries vaccination has barely started. Problems in global supply chains, including shortages in the labor market, put upward pressure on prices while possibly also negatively impacting revenue growth, as growth may be slower than expected even if demand is increasing. Wage inflation and higher raw material and energy prices may put pressure on profit margins, especially in sectors where wages are typically not high such as hospitality and manufacturing. Higher inflation typically leads to higher interest rates. The political impasse on the US debt ceiling may also push interest rates higher. All this could have a negative impact on equity valuations, especially for companies with high earnings and cash flow growth as future earnings are worth less in a high interest rate environment. A potential interest rate-driven correction could provide a good buying opportunity if the fundamental outlook of companies has not changed, but for some companies higher interest rates could also mean higher costs and lower growth.

11  |

Hypothetical Growth of $100,000 Investment in Class Y Shares³

March 31, 2016 (inception) through December 31, 2021

Top Ten Holdings as of December 31, 2021

The portfolio is actively managed and holdings are subject to change. There is no guarantee the Fund continues to invest in the securities referenced. The holdings listed exclude any temporary cash investments, are presented on an individual security basis and do not represent holdings of the issuer.

See notes to chart on page 13.

|  12

MIROVA GLOBAL SUSTAINABLE EQUITY FUND

Average Annual Total Returns – December 31, 2021³

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For most recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

13  |

MIROVA INTERNATIONAL SUSTAINABLE EQUITY FUND

Investment Goal

The Fund seeks long-term capital appreciation.

Market Conditions

2021 was generally a very positive year for global equity investors, albeit with high levels of volatility. Low interest rates and central bank support through bond buy-back programs provided an almost endless level of money supply for the economy and markets. This has pushed up valuations in equity markets, especially in high growth sectors and the US market in general. Inflation and concerns that this favorable low interest rate environment may soon come to an end have led to a sector and style rotation during 2021. Traditional energy companies and banks benefited the most, also helped by higher oil prices and higher interest rates, respectively. Renewable energy stocks underperformed significantly, having entered the year with relatively high valuations. Increased competition from oil and gas companies, combined with supply chain issues (raw material price inflation and transportation issues), further impacted margins negatively in the wind sector, and less favorable proposed regulation in California adversely impacted solar companies. Growth stocks posted generally strong results, but we also saw that many of the large technology stocks are not immune to wage inflation and supply chain issues either.

In the real world, natural disasters caused human and economic tragedies. Wildfires in southern Europe and California, floods in Germany, Austria and Belgium, and Hurricane Ida are major examples of this year’s climate change-related disasters, with a combined economic cost of well over $100 billion. Markets didn’t blink, at least not until September when it became clear that Chinese property developer China Evergrande, a group with $260 billion in debt, was in financial trouble; fears of another Lehman scenario led to a quick correction in equity prices globally. Elsewhere in the market, oil and gas prices continued their upward trajectory as demand increased while supply did not follow the same path, leading to some bankruptcies in the UK utility sector. A shortage of drivers in the transportation sector and a general lack of employees in many sectors created shortages and wage inflation. Despite all of this, earnings growth in developed markets was, on average, stronger than expected in 2021, pushing global equity markets to all-time high levels in November. However, the year ended as it started, with high volatility as some economies found themselves again in lockdown because of concerns around the Omicron variant of the Covid-19 virus.

Overview

For the 12 months ended December 31, 2021, Class Y shares of the Mirova International Sustainable Equity Fund returned 6.39% at net asset value. The Fund underperformed its benchmark, the MSCI EAFE Index (Net) which returned 11.26%.

Performance Results

There were a few drivers of the strategy’s underperformance in 2021. The strategy focuses on investing in companies positively exposed to long-term secular trends, resulting in less cyclical exposure compared to the broad market. The strategy has no exposure to traditional energy and has little exposure to large banks within the financials sector as the team doesn’t see those companies as being positively exposed to secular trends.-Energy and large banks performed very strongly in the year and lack of exposure hurt relative performance.

Alternative energy stocks Orsted and Vestas declined significantly during the year. With a strong outlook for the long-term demand environment for renewable energy, particularly offshore wind, and with both stocks having sustainable competitive advantages, the team remains comfortable continuing to hold them. Although competition has increased, updated valuation analysis incorporating significantly increased competition in their markets shows both stocks are trading at significant discounts to intrinsic value.

Over the course of 2021, we saw positive contribution from ASML, increasing sharply on solid earnings reports and attractive growth opportunities as economic activity begins to accelerate, and Novo Nordisk with high single digit revenue growth at constant currency and high single digit diluted earnings growth. Throughout the year, Novo Nordisk increased its full year revenue guidance based on early 2021 results and a more favorable outlook.

The portfolio invests in companies offering solutions to and/or expecting to benefit from the demographic, technological, environmental, and governance-related transitions that are expected to transform the world’s economies and societies during the next decade.

|  14

MIROVA INTERNATIONAL SUSTAINABLE EQUITY FUND

As trends like the digitalization of our economy, which saw strong growth as a result of Covid-19, are expected to continue to grow strongly, the portfolio remains overweight technology. There is also an underweight position in the more defensive consumer staples sector, which to some extent is offset by an overweight position in materials (mainly natural food ingredients). With many governments still committed to keeping global warming limited to a 2-degree Celsius scenario, we expect climate change to remain a driver of political debate, and the portfolio will continue to shy away from fossil fuel extraction in favor of renewables and companies focused on energy efficiency. Although cyclical exposure increased modestly during the fourth quarter because of portfolio adjustments (see below), the team continues to like the downside protection that companies with strong balance sheets, solid management teams and positive exposure to long-term secular trends potentially offer.

During the second quarter of 2021 the investment team made several changes to the portfolio including adding to existing positions in Adyen, Kubota Corp., and Prudential.

In the third quarter the team added to existing positions in Kubota Corp. and Shimano Inc. and trimmed their position in ASML Holding NV.

Portfolio changes during the fourth quarter included exited positions in Chr. Hansen Holding A/S, Coloplast A/S, Danone SA, and Brambles Ltd.

Notable new positions in 2021 included Iberdrola, MercadoLibre, , and Sanofi. Iberdrola is the world’s leading utility in wind and solar generation with about 20% of generation capacity coming from alternative energy. The company has divested completely from coal and has doubled its offshore wind pipeline in the last 18 months and expects to double its renewable capacity by 2030. It’s very well positioned to address increasing demand for alternative energy. The company has a very strong forward thinking and stable management team with a strong track record; the spread between the company’s return on capital employed (ROCE) and cost of capital has been increasing as a result of the de-risking of its generation capacity; the investment team expects this spread differential to continue to increase, leading to higher returns. The company has strong customer relationships and diversified geographic end markets. From a valuation perspective, the company is trading at an attractive valuation in absolute and relative terms, offers an attractive dividend, and is trading at what the team believes is a very significant discount to intrinsic value. Additionally, a potential spin-off of the company’s alternative energy generation assets later this year could unlock value for shareholders.

From a thematic perspective, MercadoLibre, another new position, is positively exposed to long-term secular growth in e-commerce and fintech. The company is the largest e-commerce company in Latin America, controlling 28% of the market. Penetration of e-commerce in Latin America is low at 6%, relative to the rest of the world at 18%; the region is seeing strong growth and MercadoLibre is well positioned to address this. Within fintech, almost 50% of the Latin American population is unbanked with currently 80% of transactions being paid for in cash. Access to affordable financial services is critical for poverty reduction and economic growth and MercadoLibre addresses this long-term secular trend with an integrated digital platform. From a fundamental perspective, the company benefits from economies of scale, being the largest in its market and has built up customer trust and a strong brand image. Additionally, the company has built an extensive shipping service that is both significantly faster and cheaper. Further, its integrated marketplace and payment platform increases customer convenience leading to more loyal customers. From a sustainability perspective, although some percentage of its sales are of used goods (benefiting a circular economy) and its digital payment platform allows for access to affordable financial services (reducing poverty, providing for decent work and economic growth), the impact the company creates is currently fairly low. From a risk perspective, the company manages risks around privacy and the environment adequately. From a valuation perspective, the market is underestimating the long-term revenue growth potential for the company both with regards to growth of e-commerce and digital payments in the region. Additionally, the company has spent significantly in recent years to build its shipping and logistic capabilities; as the capex spend declines in future years, margin expansion opportunity is significant given the scalability of the company’s operations.

Sanofi is a global pharmaceutical company based in France. It has a diversified business with General Medicines including Diabetes and Cardiovascular (41% sales), Specialty Care including rare diseases, oncology and immunology (30% sales), Consumer Healthcare (12% sales), and Vaccines (16% sales) in 2020.

Sanofi is well positioned to benefit from the long-term Transition Demographics. Aging populations in developed countries and high population growth in emerging countries provide long-term structural demand for medicines. For example, it is estimated that there will be more than 640 million diabetes patients by 2040 (up from 415 million in 2015), and diabetes is associated with 15% of global all-cause mortality among people 20-79 years old.

From a sustainability analysis point of view, Sanofi clearly contributes favorably to global health, and thus the United Nation’s Sustainable Development Goal 3 (Health & Well-being), with the development and production of pharmaceutical products improving quality of life and reducing global disease burden. In particular, it addresses the Access To Medicine (ATM) and Rare and Tropical Diseases sustainability opportunities, with a strategy aimed at rare diseases and vaccines for tropical conditions. The vaccine business accounted for around 16% of its total revenue in 2020 (up from around 10% in 2011). From a risk perspective, Sanofi is aware

15  |

of the key sustainability challenges it is exposed to - in particular, ethical issues in R&D, marketing and product safety - and succeeds in showing responsible management policies for most of them. Its Sustainability Opinion is “Positive” within Mirova.

With its new management team from 2019, Sanofi initialized a long-term business plan to drive top line revenue growth, improve operating margins and enhance its R&D and pipeline. Its top line growth is expected to be mainly driven by existing leading medicines, vaccines and late-stage pipeline assets. It complements internal R&D investment within its innovative platform with M&A and collaboration with other pharmaceutical companies. It has also set a clear margin target of 32%+ in 2025.

We are starting to see initial encouraging progress on this strategic plan. These long-term turnaround opportunities are not yet taken into account by the actual very attractive valuation. We took this opportunity to introduce a small position into the portfolio.

Outlook

2022 looks like it will be another positive but volatile year. While the global economy is expected to continue its recovery, many uncertainties remain the same, with no real improvement in sight for probably another six months. Covid-19, inflation and supply chain issues, central bank action, and geopolitical issues (Russia/Ukraine and US/China) are expected to be main sources of bad news for equity markets.

The Omicron variant drives the number of Covid-19 cases past previous peaks in most countries, despite higher vaccination rates. The severeness of the variant is not yet fully known, but the fact that it is far more contagious than any previous variant is expected to put more pressure on health care systems, which may lead many countries to take restrictive actions. While many sectors are now adjusted to working from home, others need clients and employees to be on-premises to function properly, and will no doubt feel the financial consequences. Eventually, we will need to learn how to live with the presence of Covid-19, but even if and when things go back to some level of normality, many of the sectors which have been hit hardest may find it difficult to secure enough employees, and even if they do it will likely be at much higher wages. Shortages in the labor market mean that there will not only be a war for talent, but high competition for employees in general. Wage inflation will put pressure on margins, especially in areas where wages are traditionally relatively low, which means that the expected economic recovery may not translate into similar earnings growth. Inflation and supply chain issues (bottlenecks in production and transportation) are expected to ease somewhat during the second half of 2022 but will likely continue to negatively impact revenue and earnings growth during the first half of the year across most sectors.

Much of the strong equity market performance of the past few years has been driven by a combination of low interest rates and central banks injecting money into the economy. Higher valuation levels in all asset classes were the result, but we expect this support to be weaker in 2022. A slowing of the rate at which central banks buy back bonds (tapering), combined with higher inflation for longer should create upward pressure on interest rates. This in turn could push equity valuations lower, reversing the trend of the past few years. On a relative basis, this could benefit the traditional Energy and Financials sectors. Regionally, this could be short-term bad news for the US market. The US has significantly outperformed Europe and emerging markets in the past few years, and its valuation premium over those markets is at a very high level. Even considering that the US economy is more flexible than the European markets and may show higher growth, one needs to be aware that many US companies are active globally, and equally that many European companies are generating revenues from the US as well.

We do expect that many of the issues which may impact 2022 will ease in the second half of the year. Covid-19 vaccination rates and development of vaccines that are more effective against new variants should allow economies to fully reopen. This in turn may ease the pressure on inflation and the supply chains more generally. With interest rates expected to stabilize or normalize at that stage, we expect the focus will return to structural, less cyclical growth. The recent United National Climate Change Conference (COP26) may have been disappointing in terms of hard short-term commitments, but it still provided a strong pathway for growth in renewable energy for decades to come. Many fossil fuel companies are now entering the space and creating more competition, but the pie is more than big enough to share with additional players. Renewable energy companies have significantly underperformed in 2021, due to a combination of high valuations coming into the year, less favorable regulation in some key markets, and supply chain issues impacting margins in the wind sector. These issues are expected to persist somewhat during the first half of the year but should ease during the second half. The underperformance during 2021 and resulting lower valuation levels provide, in our opinion, an excellent opportunity to add to those positions. Health care remains another high conviction sector. Political pressure on drug prices has eased during the Covid-19 pandemic, and a greater focus on R&D provides many growth opportunities, including for manufacturers of analytical and testing equipment. Many traditional pharma companies have not benefited from the higher general market valuation levels during the past few years, which could also offer some protection during a period of rising interest rates. We do expect the transition of our economy to a more digital model to continue and anticipate e-retail and digital payment solutions to continue to benefit. We also expect that supply chain issues in the car manufacturing sector will ease during the year, and that the transition of the car fleet towards more electric cars will continue to offer good opportunities for manufacturers of energy-efficient car components. But generally, given the expected high volatility and continued high risks to a quick but sustained economic recovery, we remain prudent, and prefer companies with high quality characteristics such as relatively low levels of debt and high visibility on recurring revenue streams.

|  16

MIROVA INTERNATIONAL SUSTAINABLE EQUITY FUND

Covid-19 stimulus spending is expected to provide a robust platform for long-term economic growth, as many governments try to stimulate their local economies by targeting investments in infrastructure. Areas like water infrastructure, sustainable and local energy production, health care, education and transport infrastructure cannot be outsourced to other low-cost countries, thus creating local jobs while offering the additional benefit of providing platforms for companies to innovate and grow. The Covid-19 crisis has also accelerated the transition toward a more digital economy. While many companies are facing high costs to deal with this transition, others are expected to benefit from it, especially solution providers in areas like cloud computing, e-retail, and fin tech. Fin tech could also be disruptive for traditional banking models, offering solutions for financial inclusion of the poorest of our population, particularly in emerging markets. Climate change awareness is high, especially after the natural disasters which have hit many parts of the world in the past several months. With November’s 2021 COP 26, we would expect many governments and multinational companies to announce strong and increased targets for renewable energy production, with multiple opportunities for renewable and traditional energy players, as the latter are also increasing their footprint in the renewable energy and hydrogen space.

Even after the recent correction in equity markets, valuations still don’t look cheap. Risks are visible at many levels which could create high volatility. A potential collapse of the Chinese property market and financial system could have serious ripple effects in the rest of the world. The Delta and Omicron variants of Covid-19 are very contagious and not enough people in developing countries are vaccinated yet, while in many emerging countries vaccination has barely started. Problems in global supply chains, including shortages in the labor market, put upward pressure on prices while possibly also having a negative impact on revenue growth, as growth may be slower than expected even if demand is increasing. Wage inflation and higher raw material and energy prices may put pressure on profit margins, especially in sectors where wages are typically not high, such as hospitality and manufacturing. Higher inflation typically leads to higher interest rates. The political impasse on the debt ceiling in the US may also push interest rates higher. All this could have a negative impact on equity valuations, especially for companies with high earnings and cash flow growth as future earnings are worth less in a high interest rate environment. A potential interest rate-driven correction could provide a good buying opportunity if the fundamental outlook of companies has not changed, but for some companies higher interest rates could also mean higher costs and lower growth.

Hypothetical Growth of $100,000 Investment in Class Y Shares²

December 28, 2018 (inception) through December 31, 2021

17  |

Top Ten Holdings as of December 31, 2021

The portfolio is actively managed and holdings are subject to change. There is no guarantee the Fund continues to invest in the securities referenced. The holdings listed exclude any temporary cash investments, are presented on an individual security basis and do not represent holdings of the issuer.

Average Annual Total Returns – December 31, 2021²

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For most recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

|  18

MIROVA U.S. SUSTAINABLE EQUITY FUND

Investment Goal

The Fund seeks long-term capital appreciation.

Market Conditions

2021 was generally a very positive year for global equity investors, albeit with high levels of volatility. Low interest rates and central bank support through bond buy-back programs provided an almost endless level of money supply for the economy and markets. This has pushed up valuations in equity markets, especially in high growth sectors and the U.S. market in general. Inflation and concerns that this favorable low interest rate environment may soon come to an end have led to a sector and style rotation during 2021. Traditional energy companies and banks benefited the most, also helped by the higher oil prices and higher interest rates respectively. Renewable energy stocks underperformed significantly, having entered the year with relatively high valuations. Increased competition from oil and gas companies, combined with supply chain issues (raw material price inflation and transportation issues), further impacted margins negatively in the wind sector, and less favorable proposed regulation in California adversely impacted solar companies. Growth stocks posted generally strong results, but we also saw that many of the large technology stocks are not immune to wage inflation and supply chain issues either.

In the real world, natural disasters caused human and economic tragedies. Wildfires in southern Europe and California, floods in Germany, Austria and Belgium, and Hurricane Ida are major examples of this year’s climate change-related disasters, with a combined economic cost of well over 100 billion U.S. dollars. Markets didn’t blink, at least not until September when it became clear that Chinese property developer China Evergrande, a group with 260 billion U.S. dollars in debt, was in financial trouble; fears of another Lehman scenario led to a quick correction in equity prices globally. Elsewhere in the market, oil and gas prices continued their upward trajectory as demand increased while supply did not follow the same path. This caused some bankruptcies in the U.K. utility sector. A shortage of drivers in the transportation sector and a general lack of employees in many sectors created shortages and wage inflation. Despite all of this, earnings growth in developed markets was, on average, stronger than expected in 2021, pushing global equity markets to all-time high levels in November. However, the year ended as it started, with high volatility as some economies found themselves again in lockdown because of concerns around the Omicron variant of the Covid-19 virus.

Performance Results

For the 12 months ended December 31, 2021, Class Y shares of the Mirova U.S. Sustainable Equity Fund returned 29.97% at net asset value. The Fund outperformed its benchmark the S&P 500® Index, which returned 28.71%.

Explanation of Fund Performance

Outperformance of the strategy is attributable to solid stock selection, particularly in Health Care. Eli Lilly performed strongly after positive trial results of its Alzheimer’s drug, and Thermo Fisher and Danaher rose on continued spending on healthcare during the pandemic and positive outlooks for longer-term healthcare spending. Stock selection in Industrials also contributed positively, with water flow and regulation product manufacturer Watts Water and waste disposal company Waste Management both performing well for the year.

Over the course of 2021, detracting from performance were First Solar and Sunrun who both declined along with other solar stocks on a proposed California decrease in net metering rates, potentially reducing the attractive economics for installing residential solar panels for California residents. Additionally, corporate sponsored childcare provider Bright Horizons, detracted from performance. While the earnings for the quarter were stronger than expected, a lack of visibility into the trajectory of occupancy levels at their childcare centers pressured the stock.

The portfolio invests in companies offering solutions to and/or expected to benefit from the demographic, technological, environmental and governance-related transitions that are expected to transform the world’s economies and societies during the next decade.

The portfolio remains overweight in Technology and Health Care. due to trends like the digitalization of our economy, which saw strong growth as a result of Covid-19, are expected to continue to grow strongly Also, support for the health care sector is expected to

19  |

show solid growth as a reaction to Covid-19 in the short-term and due to an aging population and continued focus on health and well-being in the longer-term. There is also an underweight position in the more defensive Consumer Staples sector, which to some extent is offset by an overweight position in Materials (mainly natural food ingredients). With many governments still committed to keeping global warming limited to a 2-degree Celsius scenario, we expect climate change to remain a driver of political debate and the portfolio will continue to shy away from fossil fuel extraction in favor of renewables and companies focused on energy efficiency. The team continues to prefer companies with strong balance sheets, solid management teams, and positive exposure to long-term secular trends.

During the second quarter of 2021 the investment team made several changes to the portfolio, they exited their position in Ormat Technologies Inc. and added both Sunrun Inc. and Avalara.

During the fourth quarter of 2021 the investment team took opportunities to make several changes to the portfolio, they exited positions in both Alphabet Inc. and Eaton Corp., while taking the opportunity to trim their position in both Adobe and Nvidia Corp., and adding to existing positions in Ball Corp., Mastercard, Avalara Inc., Roper Technologies Inc., Sunrun, and Xylem.

Outlook

2022 looks like it will be another positive but volatile year. While the global economy is expected to continue its recovery, many uncertainties remain the same, with no real improvement in sight for probably another six months. Covid-19, inflation and supply chain issues, central bank action, and geopolitical issues (Russia/Ukraine and U.S./China) are expected to be main sources of bad news for equity markets.

The Omicron variant drives the number of Covid-19 cases past previous peaks in most countries, despite higher vaccination rates. The severeness of the variant is not yet fully known, but the fact that it is far more contagious than any previous variant is expected to put more pressure on health care systems, which may lead many countries to take restrictive actions. While many sectors are now adjusted to working from home, others need clients and employees to be on-premises to function properly, and will no doubt feel the financial consequences. Eventually, we will need to learn how to live with the presence of Covid-19, but even if and when things go back to some level of normality, many of the sectors which have been hit hardest may find it difficult to secure enough employees, and even if they do it will likely be at much higher wages. Shortages in the labor market mean that there will not only be a war for talent, but high competition for employees in general. Wage inflation will put pressure on margins, especially in areas where wages are traditionally relatively low, which means that the expected economic recovery may not translate into similar earnings growth. Inflation and supply chain issues (bottlenecks in production and transportation) are expected to ease somewhat during the second half of 2022 but will likely continue to have a negative impact on revenue and earnings growth during the first half of the year across most sectors.

Much of the strong equity market performance of the past few years has been driven by a combination of low interest rates and central banks injecting money into the economy. Higher valuation levels in all asset classes were the result, but we expect this support to be weaker in 2022. A slowing of the rate at which central banks buy back bonds (tapering), combined with higher inflation for longer should create upward pressure on interest rates. This in turn could push equity valuations lower, reversing the trend of the past few years. On a relative basis, this could benefit the traditional energy and financials sectors. Regionally, this could be short-term bad news for the U.S. market. The U.S. has significantly outperformed Europe and emerging markets during the past few years, and its valuation premium over those markets is at a very high level. Even considering that the U.S. economy is more flexible than the European markets and may show higher growth, one needs to be aware that many U.S. companies are active globally, and equally that many European companies are generating revenues from the U.S. as well.

We do expect that many of the issues which may impact 2022 will ease in the second half of the year. Covid-19 vaccination rates and the development of vaccines that are more effective against the new variants should allow economies to fully reopen. This in turn may ease the pressure on inflation and the supply chains more generally. With interest rates expected to stabilize or normalize at that stage, we expect that the focus will return to structural, less cyclical growth. The recent COP26 climate conference may have been disappointing in terms of hard short-term commitments, but it still provided a strong pathway for growth in renewable energy for decades to come. Many fossil-fuel companies are now entering the space and creating more competition, but the pie is more than big enough to share with additional players. Renewable energy companies have significantly underperformed in 2021, due to a combination of high valuations coming into the year, less favorable regulation in some key markets, and supply chain issues impacting margins in the wind sector. These issues are expected to persist somewhat during the first half of the year but should ease during the second half. The underperformance during 2021 and resulting lower valuation levels provide in our opinion an excellent opportunity to add to those positions. Health Care remains another high conviction sector. Political pressure on drug prices has eased during the Covid-19 pandemic, and a greater focus on R&D provides many growth opportunities, including for manufactures of analytical and testing equipment. Many traditional pharma companies have not benefited from the higher general market valuation levels during the past few years, which could also offer some protections during a period of rising interest rates. We do expect the transition of our economy to a more digital model to continue and anticipate e-retail and digital payment solutions to continue to benefit. We also

|  20

MIROVA U.S. SUSTAINABLE EQUITY FUND

expect that supply chain issues in the car manufacturing sector will ease during the year, and that the transition of the car fleet towards more electric cars will continue to offer good opportunities for manufactures of energy-efficient car components. But generally, given the expected high volatility and continued high risks to a quick but sustained economic recovery, we remain prudent, and prefer companies with high quality characteristics such as relatively low levels of debt and high visibility on recurring revenue streams.

Hypothetical Growth of $100,000 Investment in Class Y Shares³

December 15, 2020 (inception) through December 31, 2021

Top Ten Holdings as of December 31, 2021

The portfolio is actively managed and holdings are subject to change. There is no guarantee the Fund continues to invest in the securities referenced. The holdings listed exclude any temporary cash investments, are presented on an individual security basis and do not represent holdings of the issuer.

21  |

Average Annual Total Returns – December 31, 2021³

Performance data shown represents past performance and is no guarantee of, and not necessarily indicative of, future results. Total return and value will vary, and you may have a gain or loss when shares are sold. Current performance may be lower or higher than quoted. For most recent month-end performance, visit im.natixis.com/performance. Performance for other share classes will be greater or less than shown based on differences in fees and sales charges. You may not invest directly in an index. Performance for periods less than one year is cumulative, not annualized. Returns reflect changes in share price and reinvestment of dividends and capital gains, if any. The table(s) do not reflect taxes shareholders might owe on any fund distributions or when they redeem their shares.

|  22

ADDITIONAL INFORMATION

The views expressed in this report reflect those of the portfolio managers as of the dates indicated. The managers’ views are subject to change at any time without notice based on changes in market or other conditions. References to specific securities or industries should not be regarded as investment advice. Because the Fund is actively managed, there is no assurance that they will continue to invest in the securities or industries mentioned.

All investing involves risk, including the risk of loss. There is no assurance that any investment will meet its performance objectives or that losses will be avoided.

ADDITIONAL INDEX INFORMATION

This document may contain references to third party copyrights, indexes, and trademarks, each of which is the property of its respective owner. Such owner is not affiliated with Natixis Investment Managers or any of its related or affiliated companies (collectively “Natixis Affiliates”) and does not sponsor, endorse or participate in the provision of any Natixis Affiliates services, funds or other financial products.

The index information contained herein is derived from third parties and is provided on an “as is” basis. The user of this information assumes the entire risk of use of this information. Each of the third party entities involved in compiling, computing or creating index information disclaims all warranties (including, without limitation, any warranties of originality, accuracy, completeness, timeliness, non-infringement, merchantability and fitness for a particular purpose) with respect to such information.

PROXY VOTING INFORMATION

A description of the Natixis Funds’ proxy voting policies and procedures is available without charge, upon request, by calling Natixis Funds at 800-225-5478; on the Natixis Funds’ website at im.natixis.com; and on the Securities and Exchange Commission’s (“SEC’s”) website at www.sec.gov. Information regarding how the Natixis Funds voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is available from the Natixis Funds’ website and the SEC’s website.

QUARTERLY PORTFOLIO SCHEDULES

The Natixis Funds file a complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year as an exhibit to its reports on Form N-PORT. The Funds’ Form N-PORT reports are available on the SEC’s website at www.sec.gov. First and third quarter schedules of portfolio holdings are also available at im.natixis.com/funddocuments. A hard copy may be requested from the Fund at no charge by calling 800-225-5478.

CFA^® and Chartered Financial Analyst^® are registered trademarks owned by the CFA Institute.

23  |

UNDERSTANDING FUND EXPENSES

As a mutual fund shareholder, you incur different costs: transaction costs, including sales charges (loads) on purchases and contingent deferred sales charges on redemptions, and ongoing costs, including management fees, distribution and/or service fees (12b-1 fees), and other fund expenses. Certain exemptions may apply. These costs are described in more detail in the Funds’ prospectus. The following examples are intended to help you understand the ongoing costs of investing in the Funds and help you compare these with the ongoing costs of investing in other mutual funds.

The first line in the table of each class of Fund shares shows the actual account values and actual Fund expenses you would have paid on a $1,000 investment in the Fund from July 1, 2021 through December 31, 2021. To estimate the expenses you paid over the period, simply divide your account value by $1,000 (for example $8,600 account value divided by $1,000 = 8.60) and multiply the result by the number in the Expenses Paid During Period column as shown for your class.

The second line in the table for each class of fund shares provides information about hypothetical account values and hypothetical expenses based on the Fund’s actual expense ratios and an assumed rate of return of 5% per year before expenses, which is not the Fund’s actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid on your investment for the period. You may use this information to compare the ongoing costs of investing in the Fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown reflect ongoing costs only, and do not include any transaction costs, such as sales charges. Therefore, the second line in the table of each fund is useful in comparing ongoing costs only, and will not help you determine the relative costs of owning funds. If transaction costs were included, total costs would be higher.

|  24

25  |

|  26

27  |

Portfolio of Investments – as of December 31, 2021

Gateway Fund

See accompanying notes to financial statements.

|  28

Portfolio of Investments – as of December 31, 2021

Gateway Fund – (continued)