Optimum Fixed Income Fund (OIFIX) 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

Item 1. Reports to Stockholders

Annual report

Optimum Fixed Income Fund

Optimum International Fund

Optimum Large Cap Growth Fund

Optimum Large Cap Value Fund

Optimum Small-Mid Cap Growth Fund

Optimum Small-Mid Cap Value Fund

March 31, 2024

Carefully consider the Funds’ investment objectives, risk factors, charges, and expenses before investing. This and other information can be found in the Funds’ prospectus and, if available, their summary prospectuses, which may be obtained by visiting optimummutualfunds.com/ literature or calling 800 914-0278. Investors should read the prospectus and, if available, the summary prospectus carefully before investing.

Table of contents

Other than Macquarie Bank Limited ABN 46 008 583 542 (“Macquarie Bank”), any Macquarie Group entity noted in this document is not an authorized deposit-taking institution for the purposes of the Banking Act 1959 (Commonwealth of Australia). The obligations of these other Macquarie Group entities do not represent deposits or other liabilities of Macquarie Bank. Macquarie Bank does not guarantee or otherwise provide assurance in respect of the obligations of these other Macquarie Group entities. In addition, if this document relates to an investment, (a) the investor is subject to investment risk including possible delays in repayment and loss of income and principal invested and (b) none of Macquarie Bank or any other Macquarie Group entity guarantees any particular rate of return on or the performance of the investment, nor do they guarantee repayment of capital in respect of the investment.

The Funds are governed by US laws and regulations.

This annual report is for the information of Optimum Fund Trust shareholders, but it may be used with prospective investors when preceded or accompanied by a current prospectus for Optimum Fund Trust and the fact sheet for the most recently completed calendar quarter. The prospectus sets forth details about charges, expenses, investment objectives, and operating policies of the investment company. You should read the prospectus carefully before you invest. The figures in this report represent past results that are not a guarantee of future results. The return and principal value of an investment in the investment company will fluctuate so that shares, when redeemed, may be worth more or less than their original cost.

Unless otherwise noted, views expressed herein are current as of March 31, 2024, and subject to change for events occurring after such date. These views are not intended to be investment advice, to forecast future events, or to guarantee future results.

The Funds are not FDIC insured and are not guaranteed. It is possible to lose the principal amount invested.

Macquarie Asset Management (MAM) is the asset management division of Macquarie Group. MAM is an integrated asset manager across public and private markets offering a diverse range of capabilities, including real assets, real estate, credit, equities, and multi-asset solutions.

All third-party marks cited are the property of their respective owners.

© 2024 Macquarie Management Holdings, Inc.

Portfolio management review

Performance review (for the year ended March 31, 2024)

Past performance does not guarantee future results.

For complete, annualized performance for Optimum Fixed Income Fund, please see the table on page 19.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 21 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Fund objective

The Fund seeks a high level of income and may also seek growth of capital.

Advisor

Delaware Management Company (DMC)

Sub-advisor

Pacific Investment Management Company LLC (PIMCO)

Market review

After a challenging year for fixed income markets in 2022 (when interest rates and credit spreads sold off in tandem) 2023 offered fixed income investors an overall improved market environment despite ongoing volatility. Government bond yields generally ended the Fund’s fiscal year lower, and credit spreads tightened as benign inflation reports increased investor confidence in a soft landing, resulting in a year-end rally across asset classes. Although many analysts had come into the fiscal period predicting a global recession given the manner and frequency with which central banks increased rates, the global economy remained resilient and most equity markets experienced growth. Over the course of the 12-month period, central bank policy and inflation remained a primary focus for investors, including discussions about the potential end of the rate hiking cycle and receding inflation.

Central banks largely prioritized controlling inflation in 2023. The US Federal Reserve continued its monetary policy tightening, with the upper end of the federal funds target range moving from 4.50% to 5.50% over the first half of the fiscal year. More recently, Fed communications conveyed a belief that rates have likely peaked. Having been behind the Fed in raising rates, the European Central Bank (ECB) hiked its deposit rate from 2.00% to 4.00% over the course of 2023. Other central banks across Canada, Australia, New Zealand, and the UK also raised rates. One outlier in developed markets was the Bank of Japan, which kept its key policy rate unchanged while further loosening its yield curve control policy.

In developed market sovereign bonds, yields rose in the second and third quarters of the Fund’s fiscal year, as the economy and inflation remained resilient, and central banks were hawkish in response. A rally in the last quarter of 2023 caused yields to fall. While Treasury yields generally ended the 12-month period ending March 31, 2024, flat, interest rate volatility throughout the fiscal year was high, with the 10-year US Treasury yield reaching a 16-year peak in October on rising fears of rates being higher for longer. However, November saw one of the bond market’s largest-ever rallies, as the Bloomberg Global Aggregate Index had its best month since the global financial crisis. Risk assets ended the 12-month period ended March 31, 2024, strongly, with most major equity indices returning 20% or more for the fiscal year. Credit spreads broadly tightened across corporates, securitized bonds, and emerging markets.

Inflation was the key economic indicator during the Fund’s fiscal year, as investor inflation fears returned in the fall of 2023, only to sharply reverse in December as the Fed signaled an end to the tightening cycle. By the first quarter of 2024, however, economic resilience, persistent fiscal momentum, and wealth effects reignited concern that the path to lower inflation may not be as smooth as initially hoped. The US Consumer Price Index (CPI) reached a low of 3% in June 2023 but touched 3.7% before softening again. It ended the Fund’s fiscal year at 3.5%.

The fiscal period ended with markets keenly focused on the Fed’s ability to transition from a tightening cycle to either a pause or easing. Expectations fluctuated from pricing in seven 2024 rate cuts in December 2023 to only three by the end of the fiscal year. Service sector pricing power resilience was a key focus at the end of the 12-month period ended March 31, 2024. The interest rate on 10-year Treasurys raced back from an exuberant 3.8% in December 2023 to 4.2% by the end of March 2024.

Portfolio management review

Optimum Fixed Income Fund

Risk markets took inflation in stride, focusing instead on a “no landing” narrative, with yield spreads for non-government sectors declining significantly, a reflection of increased exuberance. While interest rates remained at attractive levels, most credit risk sectors offered historically limited value, having returned to the bottom quartile of valuations. At the end of the Fund’s fiscal period, investors were evaluating the upcoming US presidential election and the fraught geopolitical backdrop as both Ukraine and the Middle East posed serious risks. Given that, investors’ optimism that inflation will be tamed and their enthusiasm for new technologies based on artificial intelligence (AI) may prove susceptible to negative exogenous surprises.

Source: Bloomberg, unless otherwise noted.

Fund performance

For the fiscal year ended March 31, 2024, Optimum Fixed Income Fund outperformed its benchmark, the Bloomberg US Aggregate Index. The following remarks describe factors that affected relative performance within these respective portions.

DMC

For the fiscal year ended March 31, 2024, DMC’s portion of the Optimum Fixed Income Fund outperformed its benchmark, the Bloomberg US Aggregate Index, on a gross of fees basis.

DMC’s portion of the Fund successfully navigated the volatile period by employing an agile, top-down sector allocation approach, with help from an overweight and subsequent reduction in its allocations to credit-related sectors, such as investment grade corporate, high yield, and emerging markets debt. DMC’s portion of the Fund also benefited from a modest and persistent allocation to non-agency residential mortgage-backed securities (MBS) and commercial mortgage-backed securities (CMBS). Conversely, the late-cycle transition to a neutral and eventually long-duration (a measure of a security’s sensitivity to changes in interest rates) position detracted modestly from performance as inflation fears continued to affect interest rates. DMC’s modest overweight to financials also detracted from the Fund’s performance during the fiscal period.

The Fund’s fiscal year experienced significant volatility in credit risk valuations as well as interest rates. DMC’s decision to retain an overweight to investment grade corporates through the regional banking crisis was beneficial as was its allocation to the plus sectors of high yield and emerging markets debt. However, as spreads across credit sectors tightened materially by fiscal year end, DMC monetized the strong performance by reducing credit risk in its portion of the Fund to build its liquid capital reserve and wait for what it viewed as more compelling opportunities.

In managing the higher interest rate volatility, DMC’s portion of the Fund employed a strategic long-term approach. The significant short-term volatility detracted from returns. To minimize the impact of volatility and capture long-term trends, in the initial phases of the Fed hiking cycle, DMC maintained a strategic position intended to reduce interest rate exposure. Once the 10-year Treasury yield exceeded 4%, and the Fed, along with economic indicators, began signaling late-cycle behavior, DMC sought to manage recession risk by increasing duration when interest rates rose significantly – in particular, when reaching 5% in October 2023 – and subsequently reducing that exposure once interest rates declined below 4% on “policy pivot” exuberance.

Overall exposure to high yield corporates benefited performance in DMC’s portion of the Fund during a period of earnings resilience and balance sheet strength. Among the beneficiaries of the economic recovery were cruise ship operator Carnival Corp.’s senior unsecured bonds, which performed well during the fiscal year, aided by favorable booking activity following the COVID-19 slowdown and the return to free-cash-flow generation. Additional exposure to the cruise line industry, including Royal Caribbean Cruises Ltd., was also beneficial to performance in DMC’s portion of the Fund.

DMC’s allocation to emerging market corporate securities benefited overall performance, as risk premiums declined on economic optimism. Among the stronger performers, Mexican airline operator Grupo Aeromexico SAB de CV continued to benefit from the recovery in travel.

DMC’s modest overweights to large financials Morgan Stanley and Barclays PLC detracted from performance in its portion of the Fund, as financials lagged the recovery in other components of the credit markets following the regional banking scare of March 2023. DMC’s portion of the Fund continues to hold exposure in both positions, and DMC believes the incremental yield in financials will continue to benefit total return as market attention shifts to resilience.

An allocation to securitized assets was an important driver of returns for DMC’s portion of the Fund during the fiscal year. Generally, DMC retained or increased its allocation to non-agency securitized assets such as credit risk transfer (CRT) notes, which it thinks will benefit from a strong residential real estate market. DMC’s portion of the Fund retained an overweight allocation to CMBS, which delivered strong performance. Senior fixed-rate securities generally added to performance, while the modest allocation to subordinated securities detracted from performance under the pressure of commercial real estate headlines.

During the fiscal year, DMC’s portion of the Fund used a variety of derivatives, including futures, to manage interest rate risk, swaps and swaptions to adjust the Fund’s overall exposure to certain markets, and currency forwards to increase or decrease exposure to foreign

currencies. The use of derivatives did not have a material impact on performance during the fiscal year.

PIMCO

PIMCO’s portion of the Fund outperformed its benchmark, the Bloomberg Barclays US Aggregate Index, for the fiscal year ended March 31, 2024.

Interest rate strategies contributed to performance in PIMCO’s portion of the Fund. Tactical US duration positioning, including an overweight as rates rallied during the fourth quarter of 2023, added to performance. US yield curve positioning, with an underweight to the long portion of the curve, contributed to performance as long-end rates rose more than short-end rates. Overall, non-US interest rate strategies added to performance, including overweight exposure to Australian duration in the fourth quarter of 2023 when rates rallied significantly and short exposure to UK rates at the start of the period as gilt yields rose. Lastly, emerging market local interest rate strategies contributed to performance during the Fund’s fiscal year, including an allocation to Brazilian local rates.

Spread sector strategies were positive for performance in PIMCO’s portion of the Fund. An overall overweight to agency mortgage-backed securities (MBS) added to performance as the sector outperformed like-duration Treasurys and benefited from positive carry. Holdings of select non-agency mortgages and positive security selection within AAA-rated senior collateralized loan obligations (CLOs) contributed to returns. Credit strategies contributed to performance, including an allocation to high yield corporate credit as high yield spreads tightened. Within investment grade corporate credit, an overall underweight detracted from performance for PIMCO’s portion of the Fund as the sector outperformed like-duration Treasurys. This was partially offset by positive security selection within financial names.

Currency strategies were negative for relative performance in PIMCO’s portion of the Fund, as exposure to the Japanese yen, which depreciated relative to the US dollar, and short exposure to the Polish zloty, which appreciated relative to the US dollar, detracted from performance. Long exposure to select emerging market currencies, including the Brazilian real and Mexican peso, partially offset the negative currency performance in PIMCO’s portion of the Fund.

At the end of the Fund’s fiscal year, PIMCO’s portion of the Fund was modestly underweight duration. PIMCO was neutral US duration but remains tactical given current valuations and economic fundamentals. PIMCO’s portion of the Fund maintains modest exposure to duration in dollar bloc countries as PIMCO foresees potential for faster rate normalization. It maintains short exposure to interest rates in Japan.

Regarding spread strategies, PIMCO’s portion of the Fund maintained an underweight to generic investment grade corporate credit while actively seeking compelling name and sector exposure, with a preference for senior financials. It was overweight agency MBS relative to the benchmark, favoring higher coupons that it believes are less likely to be affected by the Fed’s balance sheet unwind. PIMCO also continues to favor senior positions in securitized credit (non-agency mortgages, AAA-rated senior CLOs, and CMBS) given inherent fundamental strength and the deleveraging nature of the asset.

PIMCO remains tactical with currency positions continuing to be modest. It is long select developed market currencies and long a basket of emerging market currencies.

The use of credit default swaps, forwards, futures, interest rate swaps, options, and swaptions did not have a material impact on performance during the fiscal year within PIMCO’s portion of the Fund.

Portfolio management review

Past performance does not guarantee future results.

For complete, annualized performance for Optimum International Fund, please see the table on page 22.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 23 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Investment objective

The Fund seeks long-term growth of capital. The Fund may also seek income.

Advisor

Delaware Management Company (DMC)

Sub-advisors

Acadian Asset Management LLC (Acadian)

Baillie Gifford Overseas Limited (Baillie Gifford)

Market review

International equity markets were volatile throughout the Fund’s fiscal year ended March 31, 2024, finishing the 12-month period up 13.26% as measured by the MSCI ACWI (All Country World Index) ex USA Index (net). Investors’ concerns with interest rates and inflation drove performance during the fiscal period, with global equities rising through April 2023, selling off in May, and rallying in June as falling energy prices put fear of inflation on hold.

Central banks, including the US Federal Reserve, maintained tight monetary policy as core inflation remained sticky. When oil prices surged in August, equities sagged once again. The threat of a US government shutdown in September did little to assuage investors, who were also confronting deteriorating business conditions, challenges to China’s property market, and the onset of the Israel-Hamas war in early October.

Nonetheless, international equites registered impressive gains in November and December on the back of softer inflation data, declining crude oil prices, and rising expectations for central bank rate cuts. By this time most central banks, including the Fed, had stopped raising rates, convinced that their aggressive tightening was finally yielding results. Both inflation and overseas job markets appeared to be cooling off. Just the same, all central banks maintained their interest rates unchanged.

As a result, international equities enjoyed a strong end to the Fund’s fiscal period, rising sharply in the first quarter of 2024 on the optimism generated by expectations of rate cuts, solid corporate earnings, and lower inflation.

Overall, Japanese equities stood out, outperforming the broader international market, benefiting from a weak yen and the Bank of Japan’s decision to end its negative monetary policy. In contrast, China’s fraught real estate market, high unemployment, and slowing factory output remained cause for investor concern as did increasing tension in the Middle East.

Source: Bloomberg, unless otherwise noted.

Fund performance

For the fiscal year ended March 31, 2024, Optimum International Fund had a positive return but underperformed its benchmark, the MSCI ACWI (All Country World Index) ex USA Index (net). Relative performance differed between the Acadian and Baillie Gifford portions of the Fund. Acadian’s portion outperformed the benchmark (net of fees) while Baillie Gifford’s portion had a positive return but underperformed the benchmark. Stock selection was largely responsible in both cases, contributing to performance in Acadian’s portion of the Fund and detracting in Baillie Gifford’s portion. The information technology (IT) sector, getting a boost from the commercialization of artificial intelligence (AI), significantly contributed in both Acadian’s and Baillie Gifford’s portions of the Fund.

Acadian

Acadian focuses on its disciplined, value-focused, multifactor approach and seeks to manage the Fund with consistency, objectivity, and appropriate risk controls.

A combination of stock selection and an overweight position in information technology (IT), along with advantageous stock selection and an underweight position in consumer staples, contributed to a positive return in Acadian’s portion of the Fund. IT stocks benefited from the commercial introduction of AI applications. Meanwhile, inflation continued to erode consumer confidence, contributing to underperformance in the consumer staples sector in Acadian’s portion of the Fund during the fiscal period.

Stock selection in industrials and a combination of stock selection and an underweight position in financials detracted from performance. The financials sector benefited from prolonged elevated rates, but Acadian’s model was negative on the sector. Additionally, poor stock selection hampered the model. The decline in ocean freight rates, which peaked in 2021 and early 2022, hurt industrials in Acadian’s portion of the Fund.

Novo Nordisk A/S and Industria de Diseno Textil SA were leading contributors to relative performance in Acadian’s portion of the Fund for the fiscal year. Shares of Danish pharmaceutical giant Novo Nordisk contributed to performance, as the company benefited from demand for its semaglutide prescription drug, a key component in diabetes and weight-loss medications. Acadian’s bottom-up (stock-by-stock) selection, peer, and top-down models for the stock all ended the 12-month period positive. A position in the Spanish consumer discretionary company Industria de Diseno Textil contributed to performance after the company reported record profits. At the end of the fiscal year, Acadian’s bottom-up, peer, and top-down models all yielded positive signals for the stock. (The Fund still holds positions in Novo Nordisk and Industria de Diseno Textil.)

AP Moller - Maersk A/S and Taiwan Semiconductor Manufacturing Co. Ltd. were two leading detractors from performance in Acadian’s portion of the Fund for the fiscal year. An overweight in Danish industrials company AP Moller - Maersk detracted from relative returns in Acadian’s portion of the Fund as ocean freight rates continued to decline since peaking in early 2022. Nonetheless, at the end of the Fund’s fiscal year, Acadian’s bottom-up, peer, and top-down models all indicated positive signals for the stock. An underweight to Taiwanese IT company Taiwan Semiconductor Manufacturing detracted from performance in Acadian’s portion of the Fund as shares rose sharply on investor enthusiasm for AI.

At the end of the fiscal period, Acadian’s portion of the Fund had its largest country overweight positions in Taiwan, China, and Denmark.

The leading underweight positions were in the UK, Canada, and Japan. Sector positioning focused on IT, energy, and industrials. The biggest underweight positions were in consumer staples, financials, and communication services.

Baillie Gifford

Baillie Gifford maintains its investment philosophy and process through changing market environments. It fundamentally believes in long-term investing and that share prices ultimately follow earnings growth. Baillie Gifford is focused on finding companies whose ability to generate earnings growth is independent of a particular market environment.

Baillie Gifford’s portion of the Fund generated a positive return but underperformed its benchmark during the fiscal year. Baillie Gifford cited ongoing investor concerns about long-duration growth businesses in an environment with a multidecade-high cost of capital as well as weakness in Japanese and financials-sector holdings as reasons for the underperformance.

At the sector level, financials was the largest detractor from performance in Baillie Gifford’s portion of the Fund during the fiscal year. In the short term, financials, especially banks, outperformed as perceived beneficiaries of rising interest rates. Baillie Gifford’s portion of the Fund had little exposure to banks and thus underperformed.

Consumer discretionary holdings also detracted from performance in Baillie Gifford’s portion of the Fund. Luxury goods holdings such as Kering SA and Shiseido Co. Ltd. were weak due to their Chinese consumer exposure as spending patterns have been slow to recover to pre-COVID-19 levels. Baillie Gifford continues to hold Shiseido in its portion of the Fund because Baillie Gifford is optimistic about its restructuring toward the domestic market, and also because there is a large runway for growth among Chinese consumers over a longer-term horizon, in Baillie Gifford’s view.

IT and materials were leading contributors to performance in Baillie Gifford’s portion of the Fund. Within IT, Swedish media provider Spotify Technology SA controlled costs well and improved margins in response to a challenging interest rate environment. Taiwan Semiconductor (a holding in Baillie Gifford’s portion of the Fund) is a vital cog in the increased computing power needed of AI-driven advancements.

In materials, building-materials supplier CRH PLC was the leading contributor. Aggregate materials business CRH continued to perform well. The company plans $1.8 billion in new capital expenditures and in 2023, returned $4 billion to shareholders as buybacks and dividends. Total revenues were up 7% year over year, driven by demand in its key US and European markets. CRH’s strong

Portfolio management review

Optimum International Fund

competitive position and balance sheet mean it is well-equipped to benefit from worldwide increases in infrastructure spending, in Baillie Gifford’s view.

SAP SE, a leading German enterprise software business, was buoyed by solid operational performance. Cloud-based revenue was up 23% for the year, while the order backlog increased 25% to 13.7 billion euros. Baillie Gifford believes SAP is executing well in its effort to drive more business to the cloud and thinks SAP will benefit from developments in AI.

Pan-Asian insurance business AIA Group Ltd. detracted from performance in the Baillie Gifford portion of the Fund. The company was caught up in negative sentiment for Chinese stocks generally, a trend that Baillie Gifford has noted for some time. Nonetheless, the value of AIA’s new business grew 33% over the Fund’s fiscal year, and annualized premium revenue rose 41%. Baillie Gifford expects AIA to benefit from a recovery in demand and believes it to be well positioned to take share in the protection market, owing to the strength of its sales force.

Shares of Kering – the owner of brands including Gucci, Balenciaga, Bottega Veneta, and Yves Saint Laurent – were under pressure during the reporting period. Gucci’s growth slowed, and the recent launch of new creative director Sabato De Sarno’s first collection will take time to gain traction. As patient, long-term investors, Baillie Gifford views Kering as a high-quality business with attractive growth opportunities and continues to hold it in its portion of the Fund.

Overall, Optimum International Fund used derivatives, including foreign currency exchange contracts, during the fiscal year. However, these had a minimal effect on performance.

Portfolio management review

Past performance does not guarantee future results.

For complete, annualized performance for Optimum Large Cap Growth Fund, please see the table on page 25.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 26 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Fund objective

The Fund seeks long-term growth of capital.

Advisor

Delaware Management Company (DMC)

Sub-advisors

Los Angeles Capital Management LLC (Los Angeles Capital)

American Century Investment Management Inc. (American Century)

Market review

US equity markets produced strong gains in the 12 months ended March 31, 2024. Performance throughout the fiscal period was uneven, however, as investor confidence fluctuated in the ability of the US Federal Reserve to manage the economy, rein in inflation, and engineer a soft landing. Early in the period, many economists predicted that a recession was imminent.

Global central banks, including the Fed, maintained high interest rates throughout the Fund’s fiscal year. Over the course of the 12-month period, inflation came down but stubbornly remained above the Fed’s 2.0% target. Inflation wasn’t the only challenge. Interest rates remained high. Geopolitical concerns were elevated as the war in Ukraine continued and the conflict in Gaza erupted. Relations between the US and China remained tense.

Both consumers and investors were resilient, however, and the economy and equity markets proved stronger than expected, outperforming earlier expectations. The markets’ gain, though substantial, was not broad based; instead, global equity markets were carried by a select few companies dubbed the Magnificent Seven (Microsoft Corp., Apple Inc., NVIDIA Corp., Alphabet Inc., Amazon.com Inc., Meta Platforms Inc., and Tesla Inc.). Benefiting from technological innovation, all seven companies were perceived as having little sensitivity to the ups and downs of the macroeconomic environment. The commercialization of systems based on artificial intelligence (AI) fueled investors’ enthusiasm. Index rebalancing and very strong performance by these seven stocks resulted in unprecedented levels of index concentration. As a result, larger size proved to be a key stock characteristic this year, and higher growth also produced a modest reward.

Toward the end of the Fund’s fiscal period, riskier and more economically sensitive segments of the market enjoyed brief periods of strong performance, as investor concern dissipated, and market participants anticipated accommodative monetary conditions in the future. Whether riskier stocks can sustain market leadership seems to largely depend on earnings expectations going forward.

Source: Bloomberg, unless otherwise noted.

Fund performance

Optimum Large Cap Growth Fund posted a positive return but slightly underperformed its benchmark, the Russell 1000 Growth Index, for the Fund’s fiscal year ended March 31, 2024. American Century’s portion of the Fund had a positive return but lagged the benchmark while Los Angeles Capital’s portion of the Fund outperformed the benchmark during the fiscal year.

American Century’s portion of the Fund benefited most from its investments in the consumer discretionary and consumer staples sectors, while investments in the healthcare and financials sectors detracted from performance. In Los Angeles Capital’s portion of the Fund, investments in software and services, semiconductors, and semiconductor equipment were beneficial while positions in several large technology companies detracted from relative performance.

American Century

American Century invests in what it views as innovative, well-run companies that are reimagining their markets or creating entirely new ones. American Century takes a long-term view across the corporate

Portfolio management review

Optimum Large Cap Growth Fund

life cycle, looking for companies in the early stages of growth and holds those companies over time, allowing them to compound value for shareholders.

Within American Century’s portion of the Fund, stock selection and an underweight allocation to the consumer staples sector contributed to relative performance. The underweight resulted not from a decision on top-down sector allocation; rather, American Century did not find individual stocks that it considered compelling.

Conversely, American Century’s portion of the Fund benefited from stock selection and an overweight to the consumer discretionary sector. The sector is large and diverse and home to many companies that American Century believes are innovating and transforming their markets.

The leading individual contributor to relative performance in American Century’s portion of the Fund during the fiscal year was an overweight position in chipmaker NVIDIA. The semiconductor giant consistently and dramatically beat analysts’ already-high revenue and earnings expectations. This reflects the company’s multiyear transition and investment in its datacenter business driven by graphics processing units (GPUs) for use in AI applications. The company enjoys strong margins that should trend even higher over time given the changing business mix that emphasizes datacenter revenue and NVIDIA’s emerging software business.

Fast-casual restaurant chain Wingstop Inc. was another leading contributor in American Century’s portion of the Fund. The company enjoys strong unit growth and same-store sales growth. Its digital strategy is a key driver of transaction growth. During the Fund’s fiscal period, the company reported very strong results. New menu items and delivery platforms helped Wingstop achieve revenue and earnings that were better than expected.

Stock choices in the healthcare sector detracted the most from performance relative to the benchmark in American Century’s portion of the Fund. In general, American Century’s healthcare holdings produced positive returns but gained less than the benchmark. Healthcare equipment and supplies and biotechnology stocks hurt relative performance the most. American Century was overweight the sector because it identified healthcare companies at the forefront of several long-running secular trends it believes can promote strong, sustainable growth for years. For example, in therapeutics, American Century seeks new modes of treatment, including revolutionary gene and cell therapies, as well as breakthroughs in diabetes, Alzheimer’s disease, and obesity. These are innovative treatments that are just now beginning to be commercialized and reach populations who need them. Furthermore, advancements in medical devices have the potential to create more effective treatment options for patients.

In the financials sector, positioning in financial services and capital markets companies detracted most from relative performance in American Century’s portion of the Fund. Among financial services firms, American Century prefers companies benefiting from the growth of electronic payments. In capital markets holdings, American Century prefers financial-data providers, which it believes are less susceptible to market volatility.

Lack of exposure to Broadcom Inc. detracted from performance in American Century’s portion of the Fund. Broadcom has a strong business in network semiconductors but generally lacks competitive differentiation and offers very limited opportunities to grow, in American Century’s view.

An underweight position in Meta Platforms was another notable detractor from relative performance in American Century’s portion of the Fund. American Century had some exposure to Meta, but less than the benchmark, which hurt relative returns in a period when Meta performed very well. American Century continues to hold Meta in its portion of the Fund.

Los Angeles Capital

Los Angeles Capital addresses the need for a forward-looking systematic approach to equity management that allows for true breadth of coverage, while seeking to avoid historical biases that can dictate traditional quantitative approaches. With an investment philosophy underpinned by Investor Preference Theory^®, and an implementation process driven by a proprietary, dynamic model, Los Angeles Capital constructs portfolios that are designed to adapt and evolve to today’s economic environment.

Los Angeles Capital’s investment process regularly surveys the market to understand what characteristics are driving investor preferences today. During the Fund’s fiscal period, the market experienced bouts of optimism and doubts as investors remained focused on the handling of inflation, the trajectory of interest rates, corporate profits, and the health of the broader economy.

Los Angeles Capital’s portion of the Fund benefited from its preference for companies with greater fundamental momentum as well as those demonstrating superior management skill and organic growth. As investors sought secular growth opportunities, its portion of the Fund also benefited from companies exhibiting strong long-term growth prospects. Los Angeles Capital’s preference for companies with lower yields detracted from performance as investors rewarded higher-yielding stocks.

From an industry perspective, overweight allocations to software and services, semiconductors, and semiconductor equipment contributed to Los Angeles Capital’s portion of the Fund as the broader technology sector boasted one of the strongest returns among

sectors within the Russell 1000 Growth Index for the fiscal period. Underweight positions in several large technology companies were penalized, however, as that portion of the market performed well.

Within Los Angeles Capital’s portion of the Fund, NVIDIA and Broadcom were two notable technology-sector contributors to performance during the fiscal period. NVIDIA established itself as an early leader in the AI space and benefited from favorable analyst support relative to the broader US large-cap equity universe. Broadcom profited from the strength of its management team and organic growth relative to its peers. Investors rewarded these fundamental attributes, along with size, during the reporting period. As a result, Los Angeles Capital’s portion of the Fund benefited from its respective positioning to these two companies.

Underweight positions in Microsoft and Apple, both of which posted strong gains in the fiscal period, detracted from performance in Los Angeles Capital’s portion of the Fund. While the portfolio held positions in both companies at the end of the fiscal year due to their favorable fundamental characteristics, the exposures were below their respective benchmark weights due to Los Angeles Capital’s risk-diversification efforts. Both companies have an elevated level of concentration in the Russell 1000 Growth Index.

Overall, Optimum Large Cap Growth Fund used foreign currency exchange contracts during the fiscal year. However, these had a minimal effect on performance.

Portfolio management review

Past performance does not guarantee future results.

For complete, annualized performance for Optimum Large Cap Value Fund, please see the table on page 28.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 29 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Fund objective

The Fund seeks long-term growth of capital and may also seek income.

Advisor

Delaware Management Company (DMC)

Sub-advisors

Massachusetts Financial Services Company (MFS)

Great Lakes Advisors, LLC (Great Lakes)

Market review

Responding to the strongest inflationary episode in four decades, global central banks tightened monetary policy significantly during the Fund’s fiscal year ended March 31, 2024. Although higher rates did help ease pressure on prices, by the end of the fiscal period, it was clear that there would be more work to do before inflation returns to the US Federal Reserve’s target level of 2.0%.

During the latter five months of the fiscal period, US equity markets reached record highs, despite investors’ growing realization that an end to high interest rates is likely further down the road than had been anticipated earlier.

Though inflation has yet to reach central banks’ targets, policymakers have telegraphed their intentions to begin cutting rates in the months ahead. The prospects for easier monetary policy along with resilient global economic growth have been supportive factors for risk assets such as equities and high yield bonds. Long-term interest rates moderated during the latter half of the 12-month period, though rising government debt levels remain a concern over the medium term.

Inflation wasn’t the only challenge investors overcame during the fiscal year. Early in the Fund’s fiscal year, investors powered through turmoil in the financials sector, triggered by the sudden collapse of Silicon Valley Bank in March 2023, just prior to the start of the fiscal year.

Geopolitical concerns also came into play with the continuation of the Russia-Ukraine war and the onset of the Israel-Hamas conflict on October 7, 2023. In addition to the humanitarian concerns arising from war in the Middle East, the hostilities resulted in trade-flow disruptions between Asia and Europe as shipping traffic was routed away from the Red Sea. Relations between China and the US remained tense as the US sought to restrict the flow of advanced technologies to China, and China looked to use its industrial overcapacity to increase exports to developed markets and bolster its slow-growing domestic economy.

Investors were buoyed, however, as the threat of recession abated, and inflationary pressures eased. Corporate profits also supported market sentiment, reflecting a more resilient economy and enthusiasm for important drivers of innovation, namely artificial intelligence (AI), clean energy, and glucagon-like peptide-1 (GLP-1) drugs.

Source: Bloomberg, unless otherwise noted.

Fund performance

Optimum Large Cap Value Fund outperformed its benchmark, the Russell 1000 Value Index, for the Fund’s fiscal year ended March 31, 2024. Both the MFS and Great Lakes portions of the Fund outperformed the benchmark return, with advantageous stock selection driving outperformance. In the Great Lakes portion of the Fund, stock selection was strong in healthcare, technology, and basic materials, but offset by weakness in real estate and utilities. In the MFS portion of the Fund, stock selection was strong in healthcare, consumer discretionary, and energy, but offset by weakness in consumer staples and communication services, where an underweight sector allocation also detracted from relative performance.

Great Lakes

Great Lakes employs an integrated approach that balances quantitative analysis, fundamental research, and risk management guidelines to identify stocks of companies it believes possess attractive relative valuation and an ability to exceed market expectations. Great Lakes’ investment process has been stable through many market cycles, maintaining a consistent approach even as economic and market environments fluctuate. Within the portfolio, turnover remains relatively low versus the historical average, which is not deliberate but rather a function of Great Lakes’ positioning and bias to larger-cap market capitalization stocks. Great Lakes continues to see evidence that the largest companies in the US have the scale and financial resources available to drive market-share gains, generate high returns on capital, and reinvest in their businesses at rates far greater than their smaller-cap peers, which in theory should widen their competitive moats.

In the information technology (IT) sector, outperformance in the Great Lakes portion of the Fund was broad based and included various industry groups, namely internet services, semiconductors, communications equipment, and software. Within these buckets, the general theme of AI was the main driver, reflecting the significant ramp-up in infrastructure spending to accommodate growth across the AI verticals. The Great Lakes portion of the Fund held broad exposure to the infrastructure theme, including investments in Microsoft Corp., Broadcom Inc., and Micron Technology Inc.

Individually, the two leading contributors in the Great Lakes portion of the Fund during the fiscal year were Meta Platforms Inc., engaged in social media and online advertising, and Broadcom, a diversified semiconductor company.

In healthcare, while relative outperformance in the Great Lakes portion of the Fund was broad based, stock selection was particularly strong in pharmaceuticals. Positive stock selection largely reflected a position in Eli Lilly & Co., which benefited from the vast success of GLP-1 drugs. Great Lakes exited the position following a robust rally in the company’s shares. Relative performance also benefited from avoiding Pfizer Inc., a large component of the Russell 1000 Value benchmark. Pfizer declined by 27% due to company-specific headwinds.

The consumer services sector detracted from performance in the Great Lakes portion of the Fund due to its position in Fox Corp. The mass-media company underperformed due to its exposure to a declining TV/cable subscriber base. Great Lakes continues to hold the shares given its belief in the stock’s attractive valuation and the company’s resilient cash flow characteristics. Relative underperformance in the sector also stemmed from underweight positioning in travel-related stocks, which rallied materially in the absence of a US recession.

In real estate, underperformance in the Great Lakes portion of the Fund stemmed from ownership positions in higher-quality, long-duration real estate companies including American Tower Corp., Public Storage, Equity Lifestyle Properties Inc., and Prologis Inc., which largely lagged more cyclical stocks within the sector over the 12-month period.

Individually, the two leading detractors from performance in the Great Lakes portion of the Fund during the fiscal period were PayPal Holdings Inc. and Air Products & Chemicals Inc. PayPal, engaged in global payments systems, underperformed on concerns about competition and margins. Air Products, a leading supplier of industrial gases, underperformed on weakness in earnings, possible project delays, and increased costs for various projects.

MFS

MFS’s overall approach of using a long-term investment time horizon by investing in high-quality companies trading at inexpensive valuations did not change during the reporting period. As was the case last year, MFS continued to assess the impact of significant changes to the global economic outlook, including inflation, interest rates, uncertain monetary policy, slowing growth, and the ongoing wars in Ukraine and Gaza. MFS works to appropriately assess the risks and opportunities of companies owned within the portfolio and in its investment universe in order to appropriately position the portfolio for the years to come.

The healthcare sector contributed to relative performance in the MFS portion of the Fund due to stock selection. Within this sector, overweight positions in global health services provider The Cigna Group and health services company McKesson Corp., as well as not holding shares of global pharmaceutical company Bristol-Myers Squibb Co., supported relative results.

In the MFS portion of the Fund, holdings in the consumer discretionary and energy sectors also benefited from advantageous stock selection. In consumer discretionary, hospitality company Marriott International Inc., an out-of-benchmark holding, contributed to relative performance. Within the energy sector, there were no individual stocks, either in the portfolio or in the benchmark, that were among the top relative contributors to the MFS portion of the Fund during the fiscal year.

Stocks in other sectors that contributed to relative performance in the MFS portion of the Fund included semiconductor firm KLA Corp. and overweight positions in insurance company The Progressive Corp., global financial services firm JPMorgan Chase & Co., diversified industrial manufacturer Eaton Corp. PLC, asset management services provider KKR & Co. Inc., and financial services company American Express Co.

Portfolio management review

Optimum Large Cap Value Fund

In the MFS portion of the Fund, the consumer staples sector detracted from performance relative to the Russell 1000 Value Index, largely due to stock selection. Within this sector, holding shares of premium drinks distributor Diageo PLC, based in the UK, and global food company Nestle SA, based in Switzerland, detracted from relative performance in the MFS portion of the Fund. Although Diageo reported strong sales and earnings growth, during the fiscal year, weak volume growth disappointed investors. Nestle frustrated investors with full-year growth that came in at the low end of expectations. Both companies were out-of-benchmark investments.

Within the communication services sector, the lack of investment in social networking provider Meta Platforms Inc., which performed well during the fiscal year, also resulted in underperformance relative to the benchmark in the MFS portion of the Fund.

An overweight position and stock selection in the utilities sector hindered relative returns in the MFS portion of the Fund. Within this sector, an overweight position in energy products and services supplier Dominion Energy Inc. dampened relative performance.

The industrials sector further detracted from relative results in the MFS portion of the Fund, again largely due to stock selection. Within this sector, the lack of investment in industrial conglomerate General Electric Co. and an overweight position in global security company Northrop Grumman Corp. weakened relative results. Elsewhere, overweight positions in pharmaceutical giant Pfizer Inc. and semiconductor company Texas Instruments Inc., and not holding shares of both insurance and investment firm Berkshire Hathaway Inc. and financial services firm Wells Fargo & Co., further weighed on relative results for the MFS portion of the Fund.

Neither Great Lakes nor MFS utilized derivatives within the Fund during the fiscal year.

Portfolio management review

Performance review (for the year ended March 31, 2024)

Past performance does not guarantee future results.

For complete, annualized performance for Optimum Small-Mid Cap Growth Fund, please see the table on page 30.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 31 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Fund objective

The Fund seeks long-term growth of capital.

Advisor

Delaware Management Company (DMC)

Sub-advisors

Principal Global Investors, LLC (Principal)

Peregrine Capital Management, LLC (PCM)

Market review

US equities delivered robust gains for the Fund’s fiscal year ended March 31, 2024. For the 12-month period, the S&P 500^® Index posted a 29.9% total return. Throughout the fiscal period, a modest number of mega-cap growth companies, primarily in the technology sector, dominated the equity market’s performance overall, giving rise to the popular moniker Magnificent Seven (comprising Apple Inc., Microsoft Corp., Alphabet Inc., Amazon.com Inc., Meta Platforms Inc., NVIDIA Corp., and Tesla Inc.). Mid-cap and small-cap markets also advanced, albeit more modestly than their mega-cap brethren. The Russell 2500™ Index posted a 21.4% total return, while Russell 2500™ Growth Index advanced 21.1%, as investment style disparity was not as pronounced outside of large-caps.

The 12-month reporting period followed a tumultuous path. In the second quarter of 2023, markets rallied, reinvigorated by a series of positive developments that inspired investor confidence. US employment, consumer spending, and cooler inflation saw resilience, with the birth of the artificial intelligence (AI) boom also increasing confidence in a potential economic “soft landing.”

In the third quarter of 2023, this optimism reversed as a sharp rise in oil prices, the resumption of student loan payments, lower savings levels, and rising credit card debt shook confidence in consumer financial health. Investor focus quickly shifted from the magnitude of financial tightening needed to quell inflation to how long the Fed would maintain its tight monetary policy stance. A 20% increase in Treasury yields during the quarter also diminished soft landing hopes and drove recession fears.

Markets rebounded sharply in the fourth quarter, however, after reaching lows in late October. A cooler-than-expected Consumer Price Index (CPI) report in November and comments from US Federal Reserve Chair Jerome Powell in December that suggested rate cuts were likely to occur in 2024 drove a “risk-on” rally to end 2023. Markets maintained forward momentum following the strong finish to the calendar year despite seemingly contradictory economic signals through the first quarter of 2024. During the first quarter, investors viewed higher inflation and a stable labor market favorably, and they continued to expect a rate cut in June.

Source: Bloomberg, unless otherwise noted.

Fund performance

Optimum Small-Mid Cap Growth Fund underperformed its benchmark, the Russell 2500 Growth Index, for the fiscal year. Principal’s portion of the Fund trailed the benchmark as it was hurt by a sharp swing in market sentiment late in 2023, in which financially weaker companies outperformed on hopes of aggressive Fed rate cuts – hopes that were dialed back in the first quarter of 2024. PCM’s portion of the Fund underperformed the benchmark as a result of negative stock selection in the consumer discretionary and healthcare sectors.

Principal

Principal’s portion of the Fund lagged the Russell 2500 Growth Index’s return for the Fund’s fiscal year. The shortfall entirely occurred in the final quarter of calendar year 2023, especially in November and December, when a change in rhetoric from Fed Chair Jerome Powell signaled a more accommodative monetary policy and the beginning of interest rate cuts potentially as early as March 2024.

Portfolio management review

Optimum Small-Mid Cap Growth Fund

This gave weaker companies a new lease on life, and numerous stocks that had lagged the market earlier in the fiscal year due to weak fundamentals – as measured by poor sales growth and weak returns on equity – significantly outperformed. However, it ran counter to Principal’s focus on investing in what it views as higher-quality companies with strong fundamentals.

There were no changes to Principal’s philosophy and process during the fiscal year. The environment over the period was characterized by a continual ebb and flow over inflation expectations and the Fed’s response. This created significant volatility. Since Principal expects this environment to continue, it favors stocks that benefit from a combination of unique secular trends and improving corporate cash flows and ones that are viewed as having the ability to weather a potential economic downturn or another bout of higher inflation.

The industrials and consumer staples sectors contributed the most to performance in Principal’s portion of the Fund relative to the benchmark. In each sector, strong stock selection drove performance based on the longer-term and company-specific nature of Principal’s holdings. Within consumer staples, holdings tied to strong company-specific product launches had the most success, while the industrial winners generally were tied to strong trends in technology, such as semiconductor manufacturing and AI.

As noted, the challenging conditions that occurred late in 2023 generally affected performance in Principal’s portion of the Fund. Results lagged the benchmark in 10 of the 11 sector groups, most notably within technology and healthcare. During late November and December of 2023, many stocks, particularly in these growth sectors that had lagged the market earlier in the year based on poor sales growth and weak returns on equity, generally outperformed.

DraftKings Inc., a digital sports entertainment and gaming company, was among the largest individual contributors to performance in Principal’s portion of the Fund. Its stock appreciated after it reported robust revenue and profitability metrics that meaningfully beat expectations. Results demonstrate continued share gains and improving profitability in the online sports betting industry.

EMCOR Group Inc., a leader in electrical and mechanical construction, also contributed to Principal’s portion of the Fund as it benefited from strong momentum in semiconductor manufacturing and data center buildouts throughout the year. In addition to favorable end markets, execution on projects drove profit margin expansion and led to favorable contract awards.

Although a large contributor to absolute performance, Super Micro Computer Inc., an IT manufacturer providing server, storage, software, and support services, detracted the most from relative performance within Principal’s portion of the Fund, given Principal’s underweight position relative to the benchmark. The portfolio owned the company as a beneficiary of the widespread adoption of AI technologies, which has increased the demand for Super Micro’s AI server and server-rack products. Super Micro is a key beneficiary of strategic relationships with NVIDIA and Advanced Micro Devices, and therefore, Principal believes the momentum in AI should sustainably drive Super Micro’s growth and market penetration. Principal continued to hold the stock in its portion of the Fund at the end of the fiscal year. As the name is a large weight in the Russell 2500 Growth Index, relative performance was negative as shares continued higher after the portfolio took profits, on concerns around competition.

Vicor Corp., a leader in modular power components and systems in advanced electronics, underperformed following disappointing commentary from management that suggested a longer path than previously anticipated to scaling production for its AI-based power systems. While Principal expected Vicor’s opportunity to support NVIDIA’s latest AI graphics processing unit (GPU), the H100, to drive material multiyear sales growth, the deferred production schedule created notable uncertainty around the sales ramp during a transition period. Given these concerns, Principal exited shares during the fiscal year.

PCM

PCM’s process focuses on rapidly growing small-cap companies that PCM believes are trading at valuations that do not yet reflect that strong growth. PCM’s portion of the Fund is most overweight industrials and financials as of the end of the Fund’s fiscal year. Conversely, it is most underweight the consumer discretionary and energy sectors at fiscal year end.

The industrial and financial sectors were the largest contributors to performance for PCM’s portion of the Fund during the fiscal year. Strong stock selection across a variety of industries within the industrials sector, particularly in distributors and building products, added to performance. Both areas benefited from a resilient domestic manufacturing backdrop and a recovery in residential housing. A favorable operating environment driven by strong pricing tailwinds and new business growth aided insurance holdings in the financial sector. Additionally, capital markets holdings were strong on resilient advisory end markets and a recovery in merger and acquisition activity.

Consumer discretionary and healthcare detracted the most from performance among sectors for PCM’s portion of the Fund. Within consumer discretionary, stock selection drove most of the underperformance. In addition to weakness in specialty retailers, a position in International Game Technology PLC weighed on performance as a potential delay in the breakup of the company prevented it from keeping up with competitors. An industry

overweight and negative stock selection in healthcare equipment detracted from relative returns in healthcare along with stock selection in biotechnology.

The leading contributor to PCM’s portion of the Fund for the fiscal year was e.l.f Beauty Inc. e.l.f. sells high-end cosmetic products at affordable prices and is exposed to the ongoing demand for beauty and skin care products. e.l.f. has successfully applied a fast-fashion approach to product development and employs a digital-centric marketing strategy to retain and attract the Gen-Z cosmetic customer. e.l.f. has leveraged its superior marketing and product development strategies to gain meaningful market share. The company’s momentum continues to surprise to the upside, with shelf space gains and continued brand resonance with its key customers. This topline strength is benefiting profit margins even as it continues to invest in new products and marketing, resulting in strong fundamentals and stock performance.

Nutanix Inc., a dominant player in the enterprise infrastructure space, was another leading contributor to PCM’s portion of the Fund. Nutanix specializes in hyperconverged infrastructure, which combines storage, servers, and networking into one solution as opposed to independent silos. This approach solidified Nutanix as a key technology to adopt when enterprises use public cloud services. The heavy investment in AI and machine learning over the past year benefited Nutanix as it has further increased demand for hyperconverged infrastructure. This, paired with strong renewals and the successful transition to a subscription revenue model, reaccelerated Nutanix’s revenue growth and drove free cash flow to positive territory.

Silk Road Medical Inc. detracted the most from performance in PCM’s portion of the Fund. Silk Road develops and manufactures medical devices for the treatment of carotid artery diseases, and it generates revenue from its portfolio of products used in transcarotid artery revascularization (TCAR) procedures. TCAR is less invasive and has clinically demonstrated a reduction in risks such as long-term stroke when compared with other treatments. TCAR makes up an estimated 15-20% of the more than 170,000 carotid revascularization procedures in the US and has rapidly gained market share. In 2022 and the first half of 2023, revenue and procedures had grown by more than 35% year over year, creating a difficult comparison. Silk Road was unable to maintain its procedure momentum, however. Additionally, a decision by the Centers for Medicare & Medicaid Services to expand coverage for an alternate procedure created a new overhang on shares as investors became worried about increased competition, leading the stock to underperform. PCM no longer holds a position in Silk Road in its portion of the Fund.

Avid Bioservices Inc. also detracted from performance in PCM’s portion of the Fund. Avid Bioservices is a contract development and manufacturing organization exclusively focused on the higher-growth biologics market. The production of biologic drugs is highly complex, capital intensive, and more difficult to manufacture at scale, which makes the company an integral partner for its drug development customers. Its financial performance, however, is inevitably tied to its customers’ new biologic drug development activity and approvals, which can often be uneven. This occurred during the Fund’s fiscal year when Avid Bioservices was hurt by a slowing early-stage biotech funding environment as customers focused resources on later-stage projects over earlier-stage assets. While these later-stage products have a higher likelihood of regulatory approval, it takes longer for these projects to convert to revenue from backlog. As a result, the firm’s revenue growth slowed, with limited visibility into a sustainable recovery, causing the stock to underperform for the reporting period. Avid Bioservices is no longer a holding in PCM’s portion of the Fund.

Neither PDG nor PCM utilized derivatives within the Fund during the fiscal year.

Portfolio management review

Performance review (for the year ended March 31, 2024)

Past performance does not guarantee future results.

For complete, annualized performance for Optimum Small-Mid Cap Value Fund, please see the table on page 33.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no distribution and service fee.

The performance of Class A shares excludes the applicable sales charge. The performance of both Institutional Class shares and Class A shares reflects the reinvestment of all distributions.

Please see page 34 for a description of the index. Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index.

Fund objective

The Fund seeks long-term growth of capital.

Advisor

Delaware Management Company (DMC)

Sub-advisors

LSV Asset Management (LSV)

Cardinal Capital Management LLC (Cardinal)

Market review

Small- and mid-cap value equities in the US rose during the Fund’s fiscal year ended March 31, 2024. Macroeconomic factors dominated the stock and bond markets during the fiscal period and, along with artificial intelligence (AI)-driven euphoria, created a particularly challenging investment environment.

As typically happens during periods of heightened uncertainty associated with changing monetary and fiscal policy, as well as an increasing lack of investor confidence in the government’s ability to effectively meet its responsibilities, the equity market was short-term focused with little regard for valuations. Investors paid much higher than historical valuations for businesses with near-term visibility, while stocks with less near-term visibility traded at below-average multiples, regardless of business quality.

Domestic small-to-mid-cap value stocks slightly outpaced growth stocks during the fiscal period, unlike large-cap value stocks, which significantly lagged their growth peers. The Russell 2500^TM Index rose 21.43%, the Russell 2500 Value Index increased 21.33%, and the Russell 2500^TM Growth Index returned 21.12%. In comparison, the rally in US large-cap stocks led the Russell 1000^® Index to climb 29.87%, with the Russell 1000^® Growth Index rising by 39.00% and the Russell 1000^® Value Index returning only 20.27% for the period.

Despite the strong absolute returns, US small-cap equities did not keep up with large-cap stocks as the S&P 500^® Index gained nearly 30%. There was no style leadership during the 12-month period within small-mid-cap equities as the Russell 2500 Value Index outperformed the Russell 2500 Growth Index by 0.2% over the fiscal period. Within the Russell 2500 Value Index, the leading sectors were industrials (+36%), energy (+30%), financials (+27%), and consumer discretionary (+24%). The laggard sectors were communications services, which was up less than 1%, and utilities, which gained 4%.

Source: Bloomberg, unless otherwise noted.

Fund performance

Optimum Small-Mid Cap Value Fund underperformed its benchmark, the Russell 2500 Value Index, for the fiscal year. LSV’s portion of the Fund significantly outperformed the benchmark for the fiscal year, benefiting from strong stock selection in a variety of sectors. Cardinal’s portion of the Fund trailed the benchmark for the fiscal year, however, primarily because of stock selection across several sectors.

LSV

LSV’s portion of the Fund appreciably outperformed the benchmark index during the period. Despite the lack of style leadership in the broad market indices, the portfolio’s deeper value positioning relative to the Russell 2500 Value Index contributed as stocks that trade at a deeper discount in the benchmark performed better than the more expensive or relative value stocks in the benchmark.

The positive impact of performance relative to the benchmark was evident in good stock selection. While selection was strong across sectors, it was particularly so in the financials, utilities, consumer discretionary, and industrials sectors, where high-quality stocks trading at big discounts to the overall market outperformed. LSV finds the most attractively valued opportunities in the consumer discretionary, financials, and consumer staples sectors and is

underweight real estate, where stocks generally are more expensive. All sector bets are currently within +/- 4% relative to the benchmark sector weight in the Russell 2500 Value Index.

LSV’s portion of the Fund is broadly diversified, with 203 stocks (as of March 31, 2024), minimizing the potential of any single position to have a significant effect on relative performance. The two largest contributors to relative performance were Vistra Corp., an integrated retail electricity and power generation company, and Toll Brothers Inc., which designs, builds, markets, sells, and arranges financing for residential and commercial properties in the US. LSV’s portion of the Fund is overweight in both positions relative to the benchmark. Vistra, which owns nuclear reactors, has benefited from the emergence of AI since nuclear power is well suited to meet the electricity demands of data centers for AI. Toll Brothers has benefited from increased demand resulting from the strong economy. Both stocks remain attractively valued, and LSV held them in its portion of the Fund at the end of the fiscal year.

The two largest detractors in LSV’s portion of the Fund were Jazz Pharmaceuticals PLC, a biopharmaceutical company with a focus on oncology and neuroscience, and Atkore Inc., a leading provider of electrical, safety, and infrastructure solutions. While Jazz Pharmaceuticals recently missed earnings estimates, the company remains what LSV views as one of the most attractively priced pharmaceuticals in the small-mid-cap universe. Atkore previously had a strong run, and this stock continues to rank highly in the LSV model. LSV held Atkore in its portion of the Fund at the end of the fiscal year.

LSV’s portion of the Fund continues to own what it considers to be attractive investment opportunities across sectors and industries. LSV believes these companies are fundamentally sound, generating strong cash flows and paying solid dividends. LSV’s portion of the Fund currently trades at historically low valuations and the overall quality profile remains higher than that of the Russell 2500 Value Index. LSV continues to view the mid- to long-term prospects for its portion of the Fund as attractive and remains committed to its disciplined deep value approach regardless of market sentiment.

Cardinal

Cardinal’s investment performance did not meet the team’s expectations during the Fund’s fiscal year. However, Cardinal viewed the long-term earnings power for only one of its portfolio holdings as impaired, and that security was sold. Near-term earnings of several holdings were reduced by customers’ actions related to inventory reductions once pandemic-related supply chain disruptions normalized. The catalyst for this was the rapidly rising cost of financing as interest rates jumped. Although the number of holdings within Cardinal’s portion of the Fund experiencing earnings shortfalls was not significantly higher than usual, the magnitude of the market’s reaction was much greater than it has been historically.

The rapid increase in short-term interest rates in 2023 also detracted from relative performance in Cardinal’s portion of the Fund. This was because of the financial leverage many portfolio companies carried due to their strong free cash flow generation and the absence of an active mergers and acquisitions market for most of the fiscal period. The M&A market has historically provided a valuation floor for Cardinal’s equity holdings, but the rapidly rising cost of debt financing and sellers’ unwillingness to reduce their valuation expectations slowed activity here. As a result, several portfolio holdings traded at valuations not seen since the global financial crisis.

Although the pandemic has generally subsided, its impact is still being felt from the extreme fiscal and monetary reaction put in place to soften the disruption it caused. Cardinal believes these changes overwhelmed the typical economic cycles, and thus lower-quality stocks led the market higher during the fiscal period. For example, airlines and cruise ships have rebounded from the resurgence of travel, commodity-related businesses have benefited from pandemic-related supply shortages, and housing-related companies saw strong demand despite sharply higher rates due to a lack of supply from existing homeowners. As a result, unlike past periods of rising interest rates, Cardinal’s quality bias was a headwind to relative performance in its portion of the Fund.

From a sector perspective, the largest detractors within Cardinal’s portion of the Fund during the fiscal year were stock selection in the materials, information technology (IT), and consumer discretionary sectors, along with Cardinal’s higher weighting and stock selection within the communication services sector. In contrast, stock selection in the industrials and consumer staples sectors contributed to the performance of Cardinal’s portion of the Fund.

Materials was the weakest sector for Cardinal’s portion of the Fund relative to the benchmark. Specifically, the share price of FMC Corp. fell after the producer of agricultural chemicals reduced financial guidance despite normal usage levels by farmers as the crop protection market experienced significant inventory destocking. Cardinal continues to hold a position in FMC as the company has not lost market share, is reducing annual operating costs by $150 million, and expects revenue growth in the second half of 2024 as inventory destocking abates.

In IT, the share price of Verint Systems Inc., a provider of customer engagement software, fell after it lowered fiscal year 2024 revenue guidance due to macroeconomic-related deal slippage and the mid-year introduction of its next generation of AI bots. Although Cardinal retained a position in Verint because the company has not lost market share and has seen its pipeline grow more than 20%, the weighting was reduced as near-term visibility remains challenged.

Portfolio management review

Optimum Small-Mid Cap Value Fund

For the fiscal year, the strongest sector for Cardinal’s portion of the Fund was industrials. The most significant contributor in the sector was ESAB Corp. ESAB is a welding, cutting equipment, and gas control solutions provider. Its stock price rose throughout the year as it delivered strong results that exceeded expectations in every quarter. Management also raised its long-term revenue and operating margin goals.

Another notable contributor to relative performance for Cardinal’s portion of the Fund was BWX Technologies Inc. The share price of the specialty manufacturer of nuclear components, technologies, and services rose steadily when the company reported earnings that beat street expectations every quarter and provided guidance for 2024 that was above expectations. Management also presented a positive outlook at its recent investor day highlighting its position as the sole supplier of certain nuclear materials that enable it to capitalize on the secular growth in their use to meet increasing electrical power and medical needs.

Neither LSV nor Cardinal utilized derivatives within the Fund during the fiscal year.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table on page 20. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 4.50%, and have an annual distribution and service (12b-1) fee of 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Performance summaries

Optimum Fixed Income Fund

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

Fixed income securities and bond funds can lose value, and investors can lose principal, as interest rates rise. They also may be affected by economic conditions that hinder an issuer’s ability to make interest and principal payments on its debt. This includes prepayment risk, the risk that the principal of a bond that is held by a portfolio will be prepaid prior to maturity, at the time when interest rates are lower than what the bond was paying. A portfolio may then have to reinvest that money at a lower interest rate.

High yielding, non-investment-grade bonds (junk bonds) involve higher risk than investment grade bonds. The high yield secondary market is particularly susceptible to liquidity problems when institutional investors, such as mutual funds and certain other financial institutions, temporarily stop buying bonds for regulatory, financial, or other reasons. In addition, a less liquid secondary market makes it more difficult to obtain precise valuations of the high yield securities.

Securities in the lowest of the rating categories considered to be investment grade (that is, Baa or BBB) have some speculative characteristics.

International investments entail risks including fluctuation in currency values, differences in accounting principles, or economic or political instability. Investing in emerging markets can be riskier than investing in established foreign markets due to increased volatility, lower trading volume, and higher risk of market closures. In many emerging markets, there is substantially less publicly available information and the available information may be incomplete or misleading. Legal claims are generally more difficult to pursue.

Diversification may not protect against market risk.

If and when the Fund invests in forward foreign currency contracts or uses other investments to hedge against currency risks, the Fund will be subject to special risks, including counterparty risk.

The Fund may invest in derivatives, which may involve additional expenses and are subject to risk, including the risk that an underlying security or securities index moves in the opposite direction from what the portfolio manager anticipated. A derivatives transaction depends upon the counterparties’ ability to fulfill their contractual obligations.

Portfolio turnover is a measure of how frequently the managers buy and sell assets within a fund over a particular period. It is usually reported for a 12-month time period.

IBOR risk is the risk that changes related to the use of the London interbank offered rate (LIBOR) or similar rates (such as EONIA) could have adverse impacts on financial instruments that reference these rates. The abandonment of these rates and transition to alternative rates could affect the value and liquidity of instruments that reference them and could affect investment strategy performance.

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	Bloomberg US Aggregate Index	$10,000	$11,657
	Optimum Fixed Income Fund – Institutional Class shares	$10,000	$11,496
	Optimum Fixed Income Fund – Class A shares	$  9,550	$10,712

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 4.50% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares. Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 20. Please note additional details on pages 19 through 21.

The graph also assumes $10,000 invested in the Bloomberg US Aggregate Index as of March 31, 2014. The Bloomberg US Aggregate Index is a broad-based benchmark that measures the investment grade, US dollar-denominated, fixed-rate taxable bond market.

The Consumer Price Index (CPI), mentioned on page 1, is a measure of inflation, representing changes in prices of all goods and services purchased for consumption by households.

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table below. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 5.75%, and have an annual distribution and service (12b-1) fee of 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

International investments entail risks including fluctuation in currency values, differences in accounting principles, or economic or political instability. Investing in emerging markets can be riskier than investing in established foreign markets due to increased volatility, lower trading volume, and higher risk of market closures. In many emerging markets, there is substantially less publicly available information and the available information may be incomplete or misleading. Legal claims are generally more difficult to pursue.

The Fund may invest in derivatives, which may involve additional expenses and are subject to risk, including the risk that an underlying security or securities index moves in the opposite direction from what the portfolio manager anticipated. A derivatives transaction depends upon the counterparties’ ability to fulfill their contractual obligations.

There is no guarantee that dividend-paying stocks will continue to pay dividends.

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	MSCI ACWI ex USA Index (gross)	$10,000	$15,902
	MSCI ACWI ex USA Index (net)	$10,000	$15,167
	Optimum International Fund – Institutional Class shares	$10,000	$14,219
	Optimum International Fund – Class A shares	$  9,425	$13,071

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 5.75% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares. Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 22. Please note additional details on pages 22 through 24.

The graph also assumes $10,000 invested in the MSCI ACWI (All Country World) ex USA Index as of March 31, 2014. The MSCI ACWI ex USA Index is a free float-adjusted market capitalization weighted index that is designed to measure equity market performance across developed and emerging markets worldwide, excluding the United States. Index “gross” return approximates the maximum possible dividend reinvestment. Index “net” return approximates the minimum possible dividend reinvestment, after deduction of withholding tax at the highest possible rate.

The MSCI World Index, mentioned on page 4, represents large- and mid-cap stocks across 23 developed market countries worldwide. The index covers approximately 85% of the free float-adjusted market capitalization in each country. Index “net” return approximates the minimum possible dividend reinvestment, after deduction of withholding tax at the highest possible rate. Index “gross” return approximates the maximum possible dividend reinvestment.

Performance summaries

Optimum International Fund

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table below. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 5.75%, and have an annual distribution and service (12b-1) fee of up 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

Performance summaries

Optimum Large Cap Growth Fund

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	Russell 1000 Growth Index	$10,000	$44,042
	Optimum Large Cap Growth Fund – Institutional Class shares	$10,000	$34,230
	Optimum Large Cap Growth Fund – Class A shares	$  9,425	$31,454

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 5.75% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares. Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 25. Please note additional details on pages 25 through 27.

The graph also assumes $10,000 invested in the Russell 1000 Growth Index as of March 31, 2014. The Russell 1000 Growth Index measures the performance of the large-cap growth segment of the US equity universe. It includes those Russell 1000 companies with higher price-to-book ratios and higher forecasted growth values.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to the Russell Indexes. Russell^® is a trademark of Frank Russell Company.

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table below. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 5.75%, and have an annual distribution and service (12b-1) fee of 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

Performance summaries

Optimum Large Cap Value Fund

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	Russell 1000 Value Index	$10,000	$23,696
	Optimum Large Cap Value Fund – Institutional Class shares	$10,000	$22,296
	Optimum Large Cap Value Fund – Class A shares	$  9,425	$20,501

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 5.75% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 28. Please note additional details on pages 28 through 29.

The graph also assumes $10,000 invested in the Russell 1000 Value Index as of March 31, 2014. The Russell 1000 Value Index measures the performance of the large-cap value segment of the US equity universe. It includes those Russell 1000 companies with lower price-to-book ratios and lower forecasted growth values.

Frank Russell Company is the source and owner of the trademarks, service marks and copyrights related to the Russell Indexes. Russell^® is a trademark of Frank Russell Company.

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table below. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 5.75%, and have an annual distribution and service (12b-1) fee of 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

Performance summaries

Optimum Small-Mid Cap Growth Fund

Real estate investment trust (REIT) investments are subject to many of the risks associated with direct real estate ownership, including change in economic conditions, credit risk, and interest rate fluctuations. A REIT fund’s tax status as a regulated investment company could be jeopardized if it holds real estate directly, as a result of defaults or receive rental income from real estate holdings. Investments in small and/or medium-sized companies typically exhibit greater risk and higher volatility than larger, more established companies.

Investments in small and/or medium-sized companies typically exhibit greater risk and higher volatility than larger, more established companies.

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	Optimum Small-Mid Cap Growth Fund – Institutional Class shares	$10,000	$25,166
	Russell 2500 Growth Index	$10,000	$24,908
	Optimum Small-Mid Cap Growth Fund – Class A shares	$  9,425	$23,132

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 5.75% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 30. Please note additional details on pages 30 through 32.

The graph also assumes $10,000 invested in the Russell 2500 Growth Index as of March 31, 2014. 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 price-to-book ratios and higher forecasted growth values.

The Russell 2500 Index, mentioned on page 13, measures the performance of the small- to mid-cap segment of the US equity universe. The Russell 2500 Index is a subset of the Russell 3000^® Index, representing approximately 2,500 of the smallest securities based on a combination of their market cap and current index membership.

The S&P 500 Index, mentioned on page 13, measures the performance of 500 mostly large-cap stocks weighted by market value and is often used to represent performance of the US stock market.

Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell^® is a trademark of Frank Russell Company.

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Performance summaries

The performance quoted represents past performance and does not guarantee future results. Investment return and principal value of an investment will fluctuate so that shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than the performance quoted. Please obtain the performance data for the most recent month end by calling 800 914-0278 or visiting our website at optimummutualfunds.com/performance.

¹Returns reflect the reinvestment of all distributions and are presented both with and without the applicable sales charges described below. Returns do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for certain classes during some or all of the periods shown in the “Fund and benchmark performance” table. Expenses for each class are listed in the “Fund expense ratios” table below. Performance would have been lower had expense limitations not been in effect.

Class A shares are sold with a maximum front-end sales charge of 5.75%, and have an annual distribution and service (12b-1) fee of 0.25% of average daily net assets. Performance for Class A shares, excluding sales charges, assumes that no front-end sales charge applied.

Class C shares are sold with a contingent deferred sales charge (CDSC) of 1.00% if redeemed within one year of purchase. They are also subject to a 12b-1 fee of up to 1.00% of average daily net assets. Performance for Class C shares, excluding sales charges, assumes either that CDSCs did not apply or that the investment was not redeemed.

Institutional Class shares are not subject to a sales charge and are offered for sale exclusively to certain eligible investors. In addition, Institutional Class shares pay no 12b-1 fee.

The “Fund and benchmark performance” table and the “Performance of a $10,000 investment” graph do not reflect the deduction of taxes the shareholder would pay on Fund distributions or redemptions of Fund shares.

²The Fund’s expense ratios, as described in the most recent prospectus, are disclosed in the following “Fund expense ratios” table. The expense ratios below may differ from the expense ratios in the “Financial highlights” since they are based on different time periods and the expense ratios in the prospectus include acquired fund fees and expenses, if any. See Note 2 in “Notes to financial statements” for additional details. Please see the “Financial highlights” section in this report for the most recent expense ratios.

Real estate investment trust (REIT) investments are subject to many of the risks associated with direct real estate ownership, including change in economic conditions, credit risk, and interest rate fluctuations. A REIT fund’s tax status as a regulated investment company could be jeopardized if it holds real estate directly, as a result of defaults or receive rental income from real estate holdings. Investments in small and/or medium-sized companies typically exhibit greater risk and higher volatility than larger, more established companies.

The disruptions caused by natural disasters, pandemics, or similar events could prevent the Fund from executing advantageous investment decisions in a timely manner and could negatively impact the Fund’s ability to achieve its investment objective and the value of the Fund’s investments.

Performance of a $10,000 investment¹

For the period March 31, 2014 through March 31, 2024

		Starting value	Ending value
	Russell 2500 Value Index	$10,000	$20,967
	Optimum Small-Mid Cap Value Fund – Institutional Class shares	$10,000	$15,742
	Optimum Small-Mid Cap Value Fund – Class A shares	$  9,425	$14,473

¹The “Performance of $10,000 investment” graph assumes $10,000 invested in Class A and Institutional Class shares of the Fund on March 31, 2014, and includes the effect of a 5.75% front-end sales charge (for Class A shares) and the reinvestment of all distributions. The graph does not reflect the deduction of taxes the shareholders would pay on Fund distributions or redemptions of Fund shares.

Expense limitations were in effect for some or all of the periods shown. Performance would have been lower had expense limitations not been in effect. Current expenses are listed in the “Fund expense ratios” table on page 33. Please note additional details on pages 33 through 35.

The graph also assumes $10,000 invested in the Russell 2500 Value Index as of March 31, 2014. The Russell 2500 Value Index measures the performance of the small- to mid-cap value segment of the US equity universe. It includes those Russell 2500 companies with lower price-to-book ratios and lower forecasted growth values.

The Russell 1000 Index, mentioned on page 16, measures the performance of the large-cap segment of the US equity universe.

The Russell 1000 Growth Index, mentioned on page 16, measures the performance of the large-cap growth segment of the US equity universe. It includes those Russell 1000 companies with higher price-to-book ratios and higher forecasted growth values.

The Russell 1000 Value Index, mentioned on page 16, measures the performance of the large-cap value segment of the US equity universe. It includes those Russell 1000 companies with lower price-to-book ratios and lower forecasted growth values.

The Russell 2500 Index, mentioned on page 16, measures the performance of the small- to mid-cap segment of the US equity universe. The Russell 2500 Index is a subset of the Russell 3000^® Index, representing approximately 2,500 of the smallest securities based on a combination of their market cap and current index membership.

Performance summaries

Optimum Small-Mid Cap Value Fund

Frank Russell Company is the source and owner of the trademarks, service marks, and copyrights related to the Russell Indexes. Russell^® is a trademark of Frank Russell Company.

Index performance returns do not reflect any management fees, transaction costs, or expenses. Indices are unmanaged and one cannot invest directly in an index. Past performance does not guarantee future results.

Performance of other Fund classes will vary due to different charges and expenses.

Disclosure of Fund expenses

For the six-month period from October 1, 2023 to March 31, 2024 (Unaudited)

As a shareholder of a Fund, you incur two types of costs: (1) transaction costs, including sales charges (loads) on purchase payments, reinvested dividends, or other distributions; redemption fees; and exchange fees; and (2) ongoing costs, including management fees; distribution and service (12b-1) fees; and other Fund expenses. The following examples are intended to help you understand your ongoing costs (in dollars) of investing in a Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The examples are based on an investment of $1,000 invested at the beginning of the period and held for the entire six-month period from October 1, 2023 to March 31, 2024.

Actual Expenses

The first section of the tables shown, “Actual Fund return,” provides information about actual account values and actual expenses. You may use the information in this section of the table, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first section under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second section of the tables shown, “Hypothetical 5% return,” provides information about hypothetical account values and hypothetical expenses based on the Funds’ actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Funds’ actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in each 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 in the tables are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads), redemption fees, or exchange fees. Therefore, the second section of each table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher. The Funds’ expenses shown in the tables reflect fee waivers in effect and assume reinvestment of all dividends and distributions.

Optimum Fixed Income Fund

Expense analysis of an investment of $1,000

Optimum International Fund

Expense analysis of an investment of $1,000

Disclosure of Fund expenses

Optimum Large Cap Growth Fund

Expense analysis of an investment of $1,000

Optimum Large Cap Value Fund

Expense analysis of an investment of $1,000

Optimum Small-Mid Cap Growth Fund

Expense analysis of an investment of $1,000

Optimum Small-Mid Cap Value Fund

Expense analysis of an investment of $1,000

*“Expenses Paid During Period” are equal to the relevant Fund’s annualized expense ratio, multiplied by the average account value over the period, multiplied by 183/366 (to reflect the one-half year period).

^†Because actual returns reflect only the most recent six-month period, the returns shown may differ significantly from fiscal year returns.

In addition to the Funds’ expenses reflected above and on the previous page, each Fund also indirectly bears its portion of the fees and expenses of any investment companies (Underlying Funds), including exchange-traded funds, in which it invests. The tables above and on the previous page do not reflect the expenses of any Underlying Funds.

Security type / sector allocations

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

Security type / country and sector allocations

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

Security type / sector allocations and top 10 equity holdings

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

*To monitor compliance with the Fund’s concentration guidelines as described in the Fund’s Prospectus and Statement of Additional Information, the Information Technology sector (as disclosed herein for financial reporting purposes) is subdivided into a variety of “industries” (in accordance with the requirements of the Investment Company Act of 1940, as amended). The Information Technology sector consisted of Commercial Services, Computers, Internet, Machinery-Diversified, Semiconductors, Software, and Telecommunications. As of March 31, 2024, such amounts, as a percentage of total net assets were 0.21%, 11.27%, 0.65%, 0.40%, 14.78%, 16.13%, and 0.61%, respectively. The percentage in any such single industry will comply with the Fund’s concentration policy even if the percentage in the Information Technology sector for financial reporting purposes may exceed 25%.

Top 10 equity holdings are for informational purposes only and are subject to change at any time. They are not a recommendation to buy, sell, or hold any security.

Security type / sector allocations and top 10 equity holdings

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

Top 10 equity holdings are for informational purposes only and are subject to change at any time. They are not a recommendation to buy, sell, or hold any security.

Security type / sector allocations and top 10 equity holdings

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

Top 10 equity holdings are for informational purposes only and are subject to change at any time. They are not a recommendation to buy, sell, or hold any security.

Security type / sector allocations and top 10 equity holdings

Sector designations may be different from the sector designations presented in other Fund materials. The sector designations may represent the investment manager or sub-advisor’s internal sector classifications, which may result in the sector designations for one fund being different from another fund’s sector designations.

Top 10 equity holdings are for informational purposes only and are subject to change at any time. They are not a recommendation to buy, sell, or hold any security.

Schedules of investments

Schedules of investments

Optimum Fixed Income Fund

Schedules of investments

Optimum Fixed Income Fund

Schedules of investments

Optimum Fixed Income Fund