Summary prospectus

Delaware Opportunity Fund

January 29, 2024

(to be renamed Macquarie Opportunity Fund on or about December 31, 2024)

What is the Fund’s investment objective?

Delaware Opportunity Fund seeks long-term capital growth.

What are the Fund’s fees and expenses?

The table below describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales-charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in Delaware Funds by Macquarie​®. More information about these and other discounts is available from your financial intermediary, in the Fund’s Prospectus under the section entitled “About your account,” and in the Fund’s statement of additional information (SAI) under the section entitled “Purchasing Shares.”

Shareholder fees (fees paid directly from your investment)

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of your investment)

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. In addition, the example shows expenses for Class C shares, assuming those shares were not redeemed at the end of those periods. The example also assumes that your investment has a 5% return each year and reflects the Manager’s expense waivers and reimbursements for the 1-year contractual period and the total operating expenses without waivers for years 2 through 10. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 11% of the average value of its portfolio.

What are the Fund’s principal investment strategies?

The Fund invests primarily in mid-size companies that the Manager believes offer attractive valuation and quality characteristics. The Fund invests primarily in US companies but may also invest in foreign companies that are listed in the US. Companies with attractive valuations are those that have a lower valuation than the company’s historical average valuation and a lower valuation than the company’s competitors. Companies with quality characteristics will make shareholder friendly use of its cash flow, which would include, but is not limited to: dividend payments or increases, share repurchases, and repayment of debt. The Fund also may invest in active or passive exchange-traded funds (ETFs)

to gain exposure to such securities and up to 20% of its net assets in real estate investment trusts (REITs). The Fund may continue to hold stocks of companies that grow into larger companies and may also invest opportunistically in larger companies.

The Fund uses a “bottom-up” approach to selecting investments. The Fund uses fundamental research to search for companies that have one or more of the following: a strong balance sheet; experienced management; and stocks that are attractively priced. The Fund attempts to stay broadly diversified, but it may emphasize certain industry sectors based upon economic and market conditions.

The Fund may sell a stock if it becomes fully valued, its fundamentals have deteriorated, or alternative investments become more attractive. The Fund may also sell a stock if it grows into a large, well-established company, although it may also continue to hold such a stock irrespective of its size.

The Manager may permit its affiliate, Macquarie Investment Management Global Limited (MIMGL), to execute Fund security trades on behalf of the Manager. The Manager may also seek quantitative support from MIMGL.

What are the principal risks of investing in the Fund?

Investing in any mutual fund involves the risk that you may lose part or all of the money you invest. Over time, the value of your investment in the Fund will increase and decrease according to changes in the value of the securities in the Fund’s portfolio. An investment in the Fund may not be appropriate for all investors. The Fund’s principal risks include:

Market risk — The risk that all or a majority of the securities in a certain market — such as the stock or bond market — will decline in value because of factors such as adverse political or economic conditions, future expectations, investor confidence, or heavy institutional selling.

Company size risk — The risk that investments in small- and/or medium-sized companies may be more volatile than those of larger companies because of limited financial resources or dependence on narrow product lines.

Exchange-traded fund risk — The risks of investing in an exchange-traded fund (ETF) typically reflect the risks of the instruments in which the ETF invests. Because ETFs are investment companies, a fund will bear its proportionate share of the fees and expenses of an investment in an ETF. As a result, a fund's expenses may be higher and performance may be lower.

Real estate industry risk — This risk includes, among others: possible declines in the value of real estate; risks related to general and local economic conditions; possible lack of availability of mortgage funds; overbuilding; extended vacancies of properties; increases in competition, property taxes, and operating expenses; changes in zoning laws; costs resulting from the cleanup of, and liability to third parties resulting from, environmental problems; casualty for condemnation losses; uninsured damages from floods, earthquakes, or other natural disasters; limitations on and variations in rents; and changes in interest rates.

Liquidity risk — The possibility that investments cannot be readily sold within seven calendar days at approximately the price at which a fund has valued them.

IBOR risk — The risk that changes related to the use of the London Interbank Offered Rate (LIBOR) or similar interbank offered rates (“IBORs,” such as the Euro Overnight Index Average (EONIA)) could have adverse impacts on financial instruments that reference LIBOR or a similar rate. While some instruments may contemplate a scenario where LIBOR or a similar rate is no longer available by providing for an alternative rate setting methodology, not all instruments have such fallback provisions and the effectiveness of replacement rates is uncertain. The abandonment of LIBOR and similar rates could affect the value and liquidity of instruments that reference such rates, especially those that do not have fallback provisions. The use of alternative reference rate products may impact investment strategy performance.

Active management and selection risk — The risk that the securities selected by a fund’s management will underperform the markets, the relevant indices, or the securities selected by other funds with similar investment objectives and investment strategies. The securities and sectors selected may vary from the securities and sectors included in the relevant index.

None of the entities noted in this document is an authorized deposit-taking institution for the purposes of the Banking Act 1959 (Commonwealth of Australia) and the obligations of these entities do not represent deposits or other liabilities of Macquarie Bank Limited ABN 46 008 583 542 (Macquarie Bank). Macquarie Bank does not guarantee or otherwise provide assurance in respect of the obligations of these entities. In addition, if this document relates to an investment (a) each 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 company 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.

How has Delaware Opportunity Fund performed?

The bar chart and table below provide some indication of the risks of investing in the Fund. The Fund adopted the performance of the First Investors Opportunity Fund (Predecessor Fund) as the result of a reorganization of the Predecessor Fund into the Fund, which was consummated after the close of business on October 4, 2019 (Reorganization). The Fund had not yet commenced operations prior to the Reorganization. The bar chart shows changes in performance from year to year and the table shows how average annual total returns for the 1-, 5-, and 10-year periods compare with those of a broad measure of market performance. The past performance shown (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The returns reflect any expense caps in effect during these periods. The returns would be lower without the expense caps.

Class C and Class R shares do not have a full calendar year of performance as of the date of this Prospectus and therefore performance of the Class C and Class R shares is not included below. The performance of the Class C and Class R shares will appear in a future version of this Prospectus after Class C and Class R shares have annual returns for one complete calendar year.

The returns shown for periods ending on or prior to October 4, 2019 reflect the performance and expenses of the Predecessor Fund. The Predecessor Fund was reorganized into the Fund after the close of business on October 4, 2019. The returns shown for periods after October 4, 2019 reflect the performance and expenses of the Fund.

You may obtain the Fund’s most recently available month-end performance by calling 800 523-1918 or by visiting our website at delawarefunds.com/performance.

Calendar year-by-year total return (Class A)

During the periods illustrated in this bar chart, Class A’s highest quarterly return was 23.65% for the quarter ended December 31, 2020, and its lowest quarterly return was -35.42% for the quarter ended March 31, 2020. The maximum Class A sales charge of 5.75%, which is normally deducted when you purchase shares, is not reflected in the highest/lowest quarterly returns or in the bar chart. If this fee were included, the returns would be less than those shown. The average annual total returns in the table below do include the sales charge.

Average annual total returns for periods ended December 31, 2023

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.

After-tax performance is presented only for Class A shares of the Fund. The after-tax returns for other Fund classes may vary. Actual after-tax returns depend on the investor’s individual tax situation and

may differ from the returns shown. After-tax returns are not relevant for shares held in tax-advantaged investment vehicles such as employer-sponsored 401(k) plans and individual retirement accounts (IRAs). The after-tax returns shown are calculated using the highest individual federal marginal income tax rates in effect during the periods presented and do not reflect the impact of state and local taxes.

Who manages the Fund?

Investment manager

Delaware Management Company, a series of Macquarie Investment Management Business Trust (a Delaware statutory trust)

Sub-advisor

Macquarie Investment Management Global Limited

Purchase and redemption of Fund shares

You may purchase or redeem shares of the Fund on any day that the New York Stock Exchange (NYSE) is open for business (Business Day). Shares may be purchased or redeemed: through your financial intermediary; through the Fund’s website at delawarefunds.com/account-access; by calling 800 523-1918; by regular mail (c/o Delaware Funds by Macquarie​®, P.O. Box 534437, Pittsburgh, PA 15253-4437); by overnight courier service (c/o Delaware Funds by Macquarie Service Center, Attention: 534437, 500 Ross Street, 154-0520, Pittsburgh, PA 15262); or by wire.

For Class A and Class C shares, the minimum initial investment is generally $1,000 and subsequent investments can be made for as little as $100. The minimum initial investment for IRAs, Uniform Gifts/Transfers to Minors Act accounts, direct deposit purchase plans, and automatic investment plans is $250 and through Coverdell Education Savings Accounts is $500, and subsequent investments in these accounts can be made for as little as $25. For Class R, Institutional Class, and Class R6 shares (except those shares purchased through an automatic investment plan), there is no minimum initial purchase requirement, but certain eligibility requirements must be met. The eligibility requirements are described in this Prospectus under “Choosing a share class” and on the Fund’s website. We may reduce or waive the minimums or eligibility requirements in certain cases.

Please refer to the Fund’s prospectus and statement of additional information for more details regarding the purchase and sale of Fund shares.

Tax information

The Fund’s distributions generally are taxable to you as ordinary income, capital gains, or some combination of both, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an IRA, in which case your distributions may be taxed as ordinary income when withdrawn from the tax-advantaged account.

Payments to broker/dealers and other financial intermediaries

If you purchase shares of the Fund through a broker/dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker/dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.