Form 485BPOS CREDIT SUISSE OPPORTUNIT

CREDIT SUISSE FUNDS

Prospectus

Class A, C and I Shares

February 28, 2024

As with all mutual funds, the Securities and Exchange Commission (the "SEC") and the Commodity Futures Trading Commission have not approved these funds, nor have they passed upon the adequacy or accuracy of this Prospectus. It is a criminal offense to state otherwise.

Credit Suisse Funds are advised by Credit Suisse Asset Management, LLC.

CONTENTS

CREDIT SUISSE COMMODITY RETURN STRATEGY FUND – SUMMARY

INVESTMENT OBJECTIVE

The fund seeks total return.

FEES AND FUND EXPENSES

The accompanying tables describe the fees and expenses that you may pay if you buy, hold and sell shares of the fund.

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 Credit Suisse Funds. More information about these and other discounts is available from your financial representative and in this Prospectus on page 92 under the heading "Other Shareholder Information – Classes of Shares and Sales Charges" and on page 97 under the heading "Intermediary-Specific Sales Charge Waiver Policies," and in the fund's Statement of Additional Information ("SAI") on page 73 under the heading "Additional Purchase and Redemption Information." You may pay other fees on purchases and sales of Class I shares of the fund, such as brokerage commissions and other fees to financial intermediaries which are not reflected in the table and examples below.

  ¹​  Purchases of shares of $1 million or more may be subject to a 0.50% deferred sales charge on redemptions within 12 months of purchase.

  ²​  1.00% during the first year.

  ³​  The fund invests in Credit Suisse Cayman Commodity Fund I, Ltd., a wholly-owned subsidiary of the fund organized under the laws of the Cayman Islands (the "Subsidiary"). "Other expenses" include expenses of both the fund and the Subsidiary.

  ⁴​  Credit Suisse Commodity Strategy Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.05% of the fund's average daily net assets for Class A shares, 1.80% of the fund's average daily net assets for Class C shares and 0.80% of the fund's average daily net assets for Class I shares at least through February 28, 2025. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously waived and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursement must be paid at a date not more than thirty-six months following the applicable month during which such fees were waived or expenses were paid by Credit Suisse and the reimbursement does not cause the applicable class's aggregate expenses, on an annualized basis to exceed either (i) the applicable expense limited in effect at the time such fees were waived or such expenses were paid by Credit Suisse or (ii) the applicable expense limitation in effect at the time of such reimbursement. This contract may not be terminated before February 28, 2025.

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.

Assume you invest $10,000, the fund returns 5% annually, expense ratios remain the same and you close your account at the end of each of the time periods shown. Although your actual costs may be higher or lower, based on these assumptions, your cost would be:

PORTFOLIO TURNOVER

The computation of the fund's portfolio turnover rate for regulatory purposes excludes trades of derivatives and instruments with a maturity of one year or less. However, the fund expects to engage in frequent trading of derivatives, which could have tax consequences that impact shareholders, such as the realization of taxable short-term capital gains. In addition, the fund could incur transaction costs, such as commissions, when it buys and sells securities and other instruments. Transaction costs, which are not reflected in annual fund operating expenses or in the example, affect the fund's performance. During the most recent fiscal year ended October 31, 2023, the fund's portfolio turnover rate was 46% of the average value of its portfolio.

PRINCIPAL INVESTMENT STRATEGIES

The fund is designed to achieve positive total return relative to the performance of the Bloomberg Commodity Index Total Return ("BCOM Index"). The fund intends to invest its assets in a combination of commodity linked-derivative instruments and fixed income securities. The fund gains exposure to commodities markets by investing through the Subsidiary and in structured notes linked to the BCOM Index, other commodity indices, or the value of a particular commodity or commodity futures contract or subset of commodities or commodity futures contracts. The value of these investments will rise or fall in response to changes in the underlying index or commodity.

The fund may invest up to 25% of its total assets in the Subsidiary, a wholly-owned subsidiary of the fund organized under the laws of the Cayman Islands. The fund will invest in the Subsidiary primarily to gain exposure to the commodities markets within the limitations of the federal tax laws, rules and regulations that apply to regulated investment companies. Generally, the Subsidiary will invest in commodity-linked derivative instruments, but it will also invest in fixed income instruments, including U.S. government securities, U.S. government agency securities, corporate bonds, debentures and notes, mortgage-backed and other asset-backed securities, event-linked bonds, loan participations, bank certificates of deposit, fixed time deposits, bankers' acceptances, commercial paper and other short-term fixed income securities. The primary purpose of the fixed income instruments held by the Subsidiary will be to serve as collateral for the Subsidiary's derivative positions; however, these instruments are also expected to earn income for the Subsidiary.

The fund invests in a portfolio of fixed income securities normally having an average duration of one year or less, and emphasizes investment-grade fixed income securities.

The fund is "non-diversified," meaning that a relatively high percentage of its assets may be invested in a limited number of issuers of securities.

PRINCIPAL RISKS OF INVESTING IN THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time.

The fund is not a complete investment program and should only form a small part of a diversified portfolio. At any time, the risk of loss associated with a particular instrument in the fund's portfolio may be significantly higher than 50% of the value of the investment. Investors in the fund should be willing to assume the greater risks of potentially significant short-term share price fluctuations.

Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

COMMODITY EXPOSURE RISKS

The fund's and the Subsidiary's investments in commodity-linked derivative instruments may subject the fund to greater volatility than investments in traditional securities, particularly if the instruments involve leverage. The value of commodity-linked derivative instruments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments.

Use of leveraged commodity-linked derivatives creates an opportunity for increased return but, at the same time, creates the possibility for greater loss (including the likelihood of greater volatility of the fund's net asset value), and there can be no assurance that the fund's use of leverage will be successful.

CORRELATION RISK

Changes in the value of a hedging instrument may not match those of the investment being hedged. In addition, certain of the fund's commodity-linked derivative investments may result in the fund's performance diverging from the BCOM Index, perhaps materially. For example, a structured note can be structured to limit the loss or the gain on the investment, which would result in the fund not participating in declines or increases in the BCOM Index that exceed the limits.

CREDIT RISK

The issuer of a debt instrument or the counterparty to a contract, including derivatives contracts, may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer.

DERIVATIVES RISK

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The fund typically uses derivatives as a substitute for taking a position in the underlying asset and/or as part of a strategy designed to reduce exposure to other risks, such as interest rate or currency risk. The fund also may use derivatives for leverage. The fund's use of derivative instruments, particularly commodity-linked derivatives, involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this Prospectus, such as commodity exposure risks, correlation risk, credit risk, illiquidity risk, interest rate risk, leveraging risk, market risk and regulatory risk. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that the fund will engage in these transactions to reduce exposure to other risks when that would be beneficial.

EXPOSURE RISK

The risk associated with investments (such as derivatives) or practices (such as short selling) that increase the amount of money the fund could gain or lose on an investment.

◼  Hedged Exposure risk could multiply losses generated by a derivative or practice used for hedging purposes. Such losses should be substantially offset by gains on the hedged investment. However, while hedging can reduce or eliminate losses, it can also reduce or eliminate gains.

◼  Speculative To the extent that a derivative or practice is not used as a hedge, the fund is directly exposed to its risks. Gains or losses from speculative positions in a derivative may be much greater than the derivative's original cost. For example, potential losses from commodity-linked notes or swap agreements, from writing uncovered call options and from speculative short sales are unlimited.

FIXED INCOME RISK

The market value of fixed income investments will change in response to interest rate changes and other factors, such as changes in the effective maturities and credit ratings of fixed income investments. During periods of falling interest rates, the values of outstanding fixed income securities and related financial instruments generally rise. Conversely, during periods of rising interest rates, the values of such securities and related financial instruments generally decline. Fixed income investments are also subject to credit risk.

FOCUS RISK

The fund will be exposed to the performance of commodities in the BCOM Index, which may from time to time have a small number of commodity sectors (e.g., energy, metals or agricultural) representing a large portion of the index. As a result, the fund may be subject to greater volatility than if the index were more broadly diversified among commodity sectors. If the fund is exposed to a significant extent to a particular commodity or subset of commodities, the fund will be more exposed to the specific risks relating to such commodity or commodities and will be subject to greater volatility than if it were more broadly diversified among commodity sectors.

FUTURES CONTRACTS RISK

The risks associated with the fund's use of futures contracts and swaps and structured notes that reference the price of futures contracts include the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying reference asset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts; and (iii) if the fund has insufficient cash to meet margin requirements, the fund may need to sell other investments, including at disadvantageous times.

ILLIQUIDITY RISK

Certain fund holdings, such as commodity-linked notes and swaps, may be difficult or impossible to sell at the time and the price that the fund would like. The fund may have to lower the price, sell other holdings instead or forgo an investment opportunity. Any of these could have a negative effect on portfolio management or performance. Liquid investments may become illiquid after purchase by the fund, particularly during periods of market turmoil. There can be no assurance that a security or instrument that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by the fund.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an investment. With bonds and other fixed income instruments, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The Federal Reserve has recently begun to raise the federal funds rate as part of its efforts to address rising inflation. Interests rates are expected to continue to increase in the near future, which could adversely affect the price and liquidity of fund investments. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest on the instrument's value. In periods of market volatility, the market values of fixed income securities may be more sensitive to changes in interest rates.

LEVERAGING RISK

The fund may invest in certain derivatives that provide leveraged exposure. The fund's investment in these instruments generally requires a small investment relative to the amount of investment exposure assumed. As a result, such investments may cause the fund to lose more than the amount it invested in those instruments. The net asset value of the fund when employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the portfolio to pay interest.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sector of the economy, or the market as a whole. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, natural disasters,

recessions, or other events could have a significant impact on the fund and its investments. Market risk is common to most investments – including stocks, bonds and commodities – and the mutual funds that invest in them. The performance of "value" stocks and "growth" stocks may rise or decline under varying market conditions – for example, value stocks may perform well under circumstances in which growth stocks in general have fallen.

Bonds and other fixed income securities generally involve less market risk than stocks and commodities. However, the risk of bonds can vary significantly depending upon factors such as the issuer's creditworthiness and a bond's maturity. The bonds of some companies may be riskier than the stocks of others.

NON-DIVERSIFIED STATUS

The fund is considered a non-diversified investment company under the Investment Company Act of 1940, as amended (the "1940 Act"), and is permitted to invest a greater proportion of its assets in the securities of a smaller number of issuers than a diversified fund. As a result, the fund may be subject to greater volatility with respect to its portfolio securities than a fund that is diversified.

PORTFOLIO TURNOVER RISK

The fund expects to engage in frequent trading of derivatives. Active and frequent trading may lead to the realization and distribution to shareholders of higher short-term capital gains, which would increase their tax liability. Frequent trading also increases transaction costs, which could detract from the fund's performance.

STRUCTURED NOTE RISK

The value of a structured note will be influenced by time to maturity, level of supply and demand for the type of note, interest rate and market volatility, changes in the issuer's credit rating, and economic, legal, political, or geographic events that affect the reference asset. In addition, there may be a lag between a change in the value of the underlying reference asset and the value of the structured note.

SUBSIDIARY RISK

By investing in the Subsidiary, the fund is indirectly exposed to the risks associated with the Subsidiary's investments. The derivatives and other investments held by the Subsidiary are generally similar to those that are permitted to be held by the fund and are subject to the same risks that apply to similar investments if held directly by the fund. These risks are described elsewhere in this Prospectus.

The Subsidiary is not registered under the 1940 Act, and, unless otherwise noted in this Prospectus, is not subject to all the investor protections of the 1940 Act. However, the fund wholly owns and controls the Subsidiary, and the fund and the Subsidiary are both managed by Credit Suisse, making it unlikely that the Subsidiary will take action contrary to the interests of the fund and its shareholders. The fund's Board of Trustees has oversight responsibility for the investment activities of the fund, including its investment in the Subsidiary, and the fund's role as sole shareholder of the Subsidiary. The Subsidiary will be subject to the same investment restrictions and limitations, and follow the same compliance policies and procedures, as the fund.

Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the fund and/or the Subsidiary to continue to operate as it does currently and could adversely affect the fund.

SWAP AGREEMENTS RISK

Swap agreements involve the risk that the party with whom the fund has entered into the swap will default on its obligation to pay the fund and the risk that the fund will not be able to meet its obligations to pay the other party to the agreement.

TAX RISK

In order to qualify as a Regulated Investment Company (a "RIC") under the Internal Revenue Code of 1986, as amended, the fund must meet certain requirements regarding the source of its income, the diversification of its assets and the distribution of its income. The Internal Revenue Service has issued a ruling that income realized directly from certain types of commodity-linked derivatives would not be qualifying income. As a result, the fund's ability to realize income from direct investments in such commodity-linked derivatives as part of its investment strategy would be limited to a maximum of 10% of its gross income. To comply with the ruling, the fund seeks to gain exposure to the commodity markets primarily through investments in the Subsidiary, which invests in commodity-linked swaps, commodity futures and other derivatives, and directly through investments in commodity-linked notes. If the fund fails to qualify as a RIC, the fund will be subject to federal income tax on its net income at regular corporate rates (without reduction for

distributions to shareholders). When distributed, that income also would be taxable to shareholders as an ordinary dividend to the extent attributable to the fund's earnings and profits. If the fund were to fail to qualify as a RIC and became subject to federal income tax, shareholders of the fund would be subject to diminished returns. The fund anticipates treating income and gain from the Subsidiary and from commodity-linked notes as qualifying income.

U.S. GOVERNMENT SECURITIES RISK

Obligations of U.S. government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. government. No assurance can be given that the U.S. government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

PERFORMANCE

The accompanying bar chart and table provide an indication of the risks of investing in the fund. The bar chart shows you how performance of the fund's Class A shares has varied from year to year for up to 10 years. The table compares the fund's performance (before and after taxes) over time to that of a broad-based securities market index. The table also compares the fund's performance to the BCOM Index, which is currently composed of futures contracts on 24 physical commodities. The after-tax returns are shown for Class A shares only. The after-tax returns of other classes will vary. As with all mutual funds, past performance (before and after taxes) is not a prediction of future performance.

The fund makes updated performance available at the fund's website (www.credit-suisse.com/us/funds) or by calling Credit Suisse Funds at 877-870-2874.

Sales charges are not reflected in the accompanying bar chart, and if those charges were included, returns would be less than those shown.

AVERAGE ANNUAL TOTAL RETURNS

◼  After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts ("IRA").

PORTFOLIO MANAGEMENT

Investment manager: Credit Suisse Asset Management, LLC

Portfolio managers: The Credit Suisse Commodities Management Team is responsible for the day-to-day management of the fund. Christopher Burton, Senior Portfolio Manager and Managing Director, and Scott Ikuss, Portfolio Manager and Vice President, are the portfolio managers of the team and have been managing the fund since 2005 and 2023, respectively.

OTHER IMPORTANT INFORMATION REGARDING FUND SHARES

For important information about purchase and sale of fund shares, tax information, and payments to broker-dealers and other financial representatives, please see the "Summary of Other Important Information Regarding Fund Shares" section on page 41 of this Prospectus.

CREDIT SUISSE FLOATING RATE HIGH INCOME FUND – SUMMARY

INVESTMENT OBJECTIVE

FEES AND FUND EXPENSES

  ¹​  Purchases of shares of $1 million or more may be subject to a 0.50% deferred sales charge on redemptions within 12 months of purchase.

  ²​  1.00% during the first year.

  ³​  Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 0.95% of the fund's average daily net assets for Class A shares, 1.70% of the fund's average daily net assets for Class C shares and 0.70% of the fund's average daily net assets for Class I shares at least through February 28, 2025. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously waived and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursement must be paid at a date not more than thirty-six months following the applicable month during which such fees were waived or expenses were paid by Credit Suisse and the reimbursement does not cause the applicable class's aggregate expenses, on an annualized basis to exceed either (i) the applicable expense limited in effect at the time such fees were waived or such expenses were paid by Credit Suisse or (ii) the applicable expense limitation in effect at the time of such reimbursement. This contract may not be terminated before February 28, 2025.

EXAMPLE

PORTFOLIO TURNOVER

PRINCIPAL INVESTMENT STRATEGIES

PRINCIPAL RISKS OF INVESTING IN THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time.

Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

BELOW INVESTMENT GRADE SECURITIES RISK

Below investment grade securities (commonly referred to as "junk bonds") are regarded as being predominantly speculative as to the issuer's ability to make payments of principal and interest. Investment in such securities involves substantial risk. Issuers of below investment grade securities may be highly leveraged and may not have available to them more traditional methods of financing. Therefore, the risks associated with acquiring the securities of such issuers generally are greater than is the case with higher-rated securities.

CONFLICT OF INTEREST RISK

Affiliates of Credit Suisse may participate in the primary and secondary market for loans. Because of limitations imposed by applicable law, the presence of Credit Suisse's affiliates in the loans market may restrict the fund's ability to acquire some loans or affect the timing or price of such acquisitions.

CREDIT RISK

The issuer of a security, the borrower of a loan or the counterparty to a contract may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer. Non-investment grade securities carry a higher risk of default and should be considered speculative.

FOREIGN SECURITIES RISK

Investing outside the U.S. carries additional risks that include:

◼  Currency Risk Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign-currency denominated investments and may widen any losses. The fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies.

◼  Information Risk Key information about an issuer, security or market may be inaccurate or unavailable.

◼  Political Risk Foreign governments may expropriate assets, impose capital or currency controls and/or sanctions, impose punitive taxes, or nationalize a company or industry. Any of these actions could have a severe effect on security prices and impair the fund's ability to bring its capital or income back to the United States. Other political risks include economic policy changes, social and political instability, military action and war, such as the war between Russia and Ukraine and the conflict between Israel and Hamas.

ILLIQUIDITY RISK

Due to restrictions on transfers in loan agreements and the nature of the private syndication of Senior Loans including, for example, the lack of publicly available information, some Senior Loans are not as easily purchased or sold as publicly traded securities. No active trading market may exist for certain Senior Loans and other fixed income instruments and some Senior Loans may be subject to restrictions on resale. Secondary markets may be subject to irregular trading activity and wide bid/ask spreads. This may impair the ability of the fund to sell or realize the full value of its Senior Loans or other fixed income instruments in the event of a need to liquidate such assets.

Transactions in Senior Loans may settle on a delayed basis, resulting in the proceeds from the sale of Senior Loans not being readily available to make additional investments or to meet the fund's redemption obligations. To the extent the extended settlement process gives rise to short-term liquidity needs, the fund may hold cash, sell investments or temporarily borrow from banks or other lenders.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an investment. With loans, bonds and other fixed income securities, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The Federal Reserve has raised the federal funds rate as part of its efforts to address rising inflation. If interests rates continue to increase in the near future, this could adversely affect the price and liquidity of fund investments. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest on the instrument's value. In periods of market volatility, the market values of fixed income securities may be more sensitive to changes in interest rates. The impact of interest rate changes on floating rate instruments is typically mitigated by the periodic interest rate adjustments of the instruments.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sector of the economy, or the market as a whole. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, natural disasters, recessions, or other events could have a significant impact on the fund and its investments. Market risk is common to most investments – including stocks, bonds and commodities – and the mutual funds that invest in them. The performance of "value" stocks and "growth" stocks may rise or decline under varying market conditions – for example, value stocks may perform well under circumstances in which growth stocks in general have fallen.

Bonds and other fixed income securities generally involve less market risk than stocks and commodities. However, the risk of bonds can vary significantly depending upon factors such as the issuer's creditworthiness and a bond's maturity. The bonds of some companies may be riskier than the stocks of others.

PREPAYMENT RISK

In a declining interest rate environment, prepayment of loans and other fixed income instruments with high stated interest rates may increase. In such circumstances, the fund may have to reinvest the prepayment proceeds at lower yields.

REFERENCE RATE REPLACEMENT RISK

The Fund may be exposed to financial instruments that recently transitioned from, or continue to be tied to, the London Interbank Offered Rate ("LIBOR") to determine payment obligations, financing terms, hedging strategies or investment value.

The United Kingdom's Financial Conduct Authority ("FCA"), which regulates LIBOR, has ceased publishing all LIBOR settings. In April 2023, however, the FCA announced that some USD LIBOR settings will continue to be published under a synthetic methodology until September 30, 2024 for certain legacy contracts. The Secured Overnight Financing Rate ("SOFR") is a broad measure of the cost of borrowing cash overnight collateralized by U.S. Treasury securities in the repurchase agreement ("repo") market and has been used increasingly on a voluntary basis in new instruments and transactions. Under U.S. regulations that implement a statutory fallback mechanism to replace LIBOR, benchmark rates based on SOFR have replaced LIBOR in certain financial contracts.

Neither the effect of the LIBOR transition process nor its ultimate success can yet be known. While some existing LIBOR-based instruments may contemplate a scenario where LIBOR is no longer available by providing for an alternative rate-setting methodology, there may be significant uncertainty regarding the effectiveness of any such alternative methodologies to replicate LIBOR. Not all existing LIBOR-based instruments may have alternative rate-setting provisions and there remains uncertainty regarding the willingness and ability of issuers to add alternative rate-setting provisions in certain existing instruments. Parties to contracts, securities or other instruments using LIBOR may disagree on transition rates or the application of transition regulation, potentially resulting in uncertainty of performance and the possibility of litigation. The Fund may have instruments linked to other interbank offered rates that may also cease to be published in the future.

SENIOR LOANS RISKS

Senior Loans are subject to the risk that a court could subordinate a Senior Loan, which typically holds the most senior position in the issuer's capital structure, to presently existing or future indebtedness or take other action detrimental to the holders of Senior Loans. Senior Loans are also subject to heightened prepayment risk, as they usually have mandatory and optional prepayment provisions. Senior Loans are subject to the risk that the value of the collateral, if any, securing a loan may decline, be insufficient to meet the obligations of the borrower, or be difficult to liquidate.

VALUATION RISK

The lack of an active trading market may make it difficult to obtain an accurate price for an instrument held by the fund.

PERFORMANCE

AVERAGE ANNUAL TOTAL RETURNS

PORTFOLIO MANAGEMENT

Investment manager: Credit Suisse Asset Management, LLC

Portfolio managers: The Credit Suisse Credit Investments Group is responsible for the day-to-day portfolio management of the fund. The current team members are John G. Popp, a Managing Director of Credit Suisse, Louis I. Farano, a Managing Director of Credit Suisse, David J. Mechlin, a Managing Director of Credit Suisse, Joshua Shedroff, a Managing Director of Credit Suisse, and Wing Chan, a Managing Director of Credit Suisse. Messrs. Popp, Farano, Mechlin and Shedroff and Ms. Chan have been members of the Credit Suisse Credit Investments Group since 1997, 1998, 2006, 2006, 2008 and 2005, respectively.

OTHER IMPORTANT INFORMATION REGARDING FUND SHARES

For important information about purchase and sale of fund shares, tax information, and payments to broker-dealers and other financial representatives, please see the "Summary of Other Important Information Regarding Fund Shares" section on page 41 of this Prospectus.

CREDIT SUISSE STRATEGIC INCOME FUND – SUMMARY

INVESTMENT OBJECTIVE

FEES AND FUND EXPENSES

  ¹​  Purchases of shares of $1 million or more may be subject to a 0.50% deferred sales charge on redemptions within 12 months of purchase.

  ²​  1.00% during the first year.

  ³​  Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.04% of the fund's average daily net assets for Class A shares, 1.79% of the fund's average daily net assets for Class C shares and 0.79% of the fund's average daily net assets for Class I shares at least through February 28, 2025. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously waived and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursement must be paid at a date not more than thirty-six months following the applicable month during which such fees were waived or expenses were paid by Credit Suisse and the reimbursement does not cause the applicable class's aggregate expenses, on an annualized basis to exceed either (i) the applicable expense limited in effect at the time such fees were waived or such expenses were paid by Credit Suisse or (ii) the applicable expense limitation in effect at the time of such reimbursement. This contract may not be terminated before February 28, 2025.

EXAMPLE

PORTFOLIO TURNOVER

PRINCIPAL INVESTMENT STRATEGIES

PRINCIPAL RISKS OF THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time.

Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

BELOW INVESTMENT GRADE SECURITIES RISK

Below investment grade securities (commonly referred to as "junk bonds") are regarded as being predominantly speculative as to the issuer's ability to make payments of principal and interest. Investment in such securities involves substantial risk. Issuers of below investment grade securities may be highly leveraged and may not have available to them more traditional methods of financing. Therefore, the risks associated with acquiring the securities of such issuers generally are greater than is the case with higher-rated securities.

COLLATERALIZED LOAN OBLIGATIONS RISK

CLOs are subject to the risk of substantial losses due to actual defaults, decrease of market value due to collateral defaults and disappearance of subordinate tranches, market anticipation of defaults, and investor aversion to CLO securities as a class. The risks of CLOs depend largely on the type of the underlying loans and the tranche of CLOs in which the fund invests. In addition, CLOs carry risks including interest rate risk and credit risk.

CONFLICT OF INTEREST RISK

Affiliates of Credit Suisse may act as underwriter, lead agent or administrative agent for loans and participate in the secondary market for loans. Because of limitations imposed by applicable law, the presence of Credit Suisse's affiliates in the primary and secondary markets for loans may restrict the fund's ability to acquire some loans or affect the timing or price of such acquisitions.

CONVERTIBLE SECURITIES RISK

The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer's credit rating or the market's perception of the issuer's creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of

market and issuer risks that apply to the underlying common stock. The fund, as a holder of convertible bonds, may at times be allocated phantom taxable income from bond issuers, potentially retroactively or otherwise without notice.

CREDIT RISK

The issuer of a security, the borrower of a loan or the counterparty to a contract, including derivatives contracts, may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer. Non-investment grade securities carry a higher risk of default and should be considered speculative.

DERIVATIVES RISK

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, instrument or index. The fund may use derivatives as part of a strategy designed to reduce exposure to certain risks, such as currency risk. Derivatives are subject to a number of risks described elsewhere in this Prospectus, such as illiquidity risk, interest rate risk, market risk and regulatory risk. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that the fund will engage in these transactions to reduce exposure to other risks when that would be beneficial.

EXTENSION RISK

An unexpected rise in interest rates may extend the life of a mortgage-backed security beyond the expected prepayment time, typically reducing the security's value.

FOREIGN SECURITIES RISK

Investing outside the U.S. carries additional risks that include:

◼  Currency Risk Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign-currency-denominated investments and may widen any losses. The fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies.

◼  Information Risk Key information about an issuer, security or market may be inaccurate or unavailable.

◼  Political Risk Foreign governments may expropriate assets, impose capital or currency controls, and/or sanctions impose punitive taxes, or nationalize a company or industry. Any of these actions could have a severe effect on security prices and impair the fund's ability to bring its capital or income back to the U.S. Other political risks include economic policy changes, social and political instability, military action and war, such as the war between Russia and Ukraine that began in February 2022.

FUTURES CONTRACTS RISK

The risks associated with the fund's use of futures contracts include the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying reference asset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts; and (iii) if the fund has insufficient cash to meet margin requirements, the fund may need to sell other investments, including at disadvantageous times.

HEDGED EXPOSURE RISK

The fund's hedging activities could multiply losses generated by a derivative used for hedging purposes. Such losses should be substantially offset by gains on the hedged investment. However, while hedging can reduce or eliminate losses, it can also reduce or eliminate gains.

ILLIQUIDITY RISK

Certain portfolio holdings may be difficult or impossible to sell at the time and the price that the fund would like. The fund may have to lower the price, sell other holdings instead or forgo an investment opportunity. Any of these could have a negative effect on portfolio management or performance. Liquid investments may become illiquid after purchase by the fund, particularly during periods of market turmoil. There can be no assurance that a security or instrument that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by the fund.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an investment. With bonds and other debt instruments, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The Federal Reserve has raised the federal funds rate as part of its efforts to address rising inflation. If interest rates continue to increase in the near future, this could adversely affect the price and liquidity of fund investments. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest rates on the instrument's value. In periods of market volatility, the market values of fixed income securities may be more sensitive to changes in interest rates.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sector of the economy, or the market as a whole. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, natural disasters, recessions, or other events could have a significant impact on the fund and its investments. Market risk is common to most investments – including stocks, bonds and commodities – and the mutual funds that invest in them. The performance of "value" stocks and "growth" stocks may rise or decline under varying market conditions – for example, value stocks may perform well under circumstances in which growth stocks in general have fallen.

Bonds and other fixed income securities generally involve less market risk than stocks and commodities. However, the risk of bonds can vary significantly depending upon factors such as the issuer's creditworthiness and a bond's maturity. The bonds of some companies may be riskier than the stocks of others.

MORTGAGE- AND ASSET-BACKED SECURITIES RISKS

The value of the fund's mortgage-backed securities can fall if the owners of the underlying mortgages pay off their mortgages sooner than expected, which could happen when interest rates fall, or later than expected, which could happen when interest rates rise. If the underlying mortgages are paid off sooner than expected, the fund may have to reinvest this money in mortgage-backed or other securities that have lower yields.

Payment of interest and repayment of principal may be impacted by the cash flows generated by the assets backing asset-backed securities. The value of the fund's asset-backed securities may also be affected by changes in interest rates, the availability of information concerning the interests in and structure of the pools of purchase contracts, financing leases or sales agreements that are represented by these securities, the creditworthiness of the servicing agent for the pool, the originator of the loans or receivables, or the entities that provide any supporting letters of credit, surety bonds, or other credit enhancements.

PREPAYMENT RISK

In a declining interest rate environment, prepayment of loans and other fixed income instruments with high stated interest rates may increase. In such circumstances, the fund may have to reinvest the prepayment proceeds at lower yields.

SENIOR LOANS RISKS

Senior Loans are subject to the risk that a court could subordinate a Senior Loan, which typically holds the most senior position in the issuer's capital structure, to presently existing or future indebtedness or take other action detrimental to the holders of Senior Loans. Senior Loans are also subject to heightened prepayment risk, as they usually have mandatory and optional prepayment provisions. Senior Loans are subject to the risk that the value of the collateral, if any, securing a loan may decline, be insufficient to meet the obligations of the borrower, or be difficult to liquidate.

SHORT POSITION RISK

The fund may enter into a short position through a futures contract or swap agreement or by selling a security short. Taking short positions involves leverage of the fund's assets and presents various risks. If the price of the asset, instrument or market on which the fund has taken a short position increases, then the fund will incur a loss equal to the increase in price from the time that the short position was entered into plus any premiums and interest paid to a third party in connection with the short sale. Therefore, taking short positions involves the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. The fund's loss on a short sale could theoretically be unlimited in a case where the fund is unable, for whatever reason, to close out its short position.

U.S. GOVERNMENT SECURITIES RISK

Obligations of U.S. government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. government. No assurance can be given that the U.S. government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

VALUATION RISK

The lack of an active trading market may make it difficult to obtain an accurate price for an instrument held by the fund. Many derivative instruments are not actively traded.

PERFORMANCE

AVERAGE ANNUAL TOTAL RETURNS

PORTFOLIO MANAGEMENT

Investment manager: Credit Suisse Asset Management, LLC

Subadviser: Credit Suisse Asset Management Limited ("Credit Suisse UK")

Portfolio managers: The Credit Suisse Credit Investments Group is responsible for the day-to-day portfolio management of the fund. The current team members are John G. Popp, a Managing Director of Credit Suisse, Andrew H. Marshak, a Managing Director of Credit Suisse UK, Louis I. Farano, a Managing Director of Credit Suisse, David J. Mechlin, a Managing Director of Credit Suisse, Joshua Shedroff, a Managing Director of Credit Suisse and Wing Chan, a Managing Director of Credit Suisse. Messrs. Popp, Marshak, Farano, Mechlin and Shedroff and Ms. Chan have been members of the Credit Suisse Credit Investments Group since 1997, 1997, 1998, 2006, 2006, 2008 and 2005, respectively, and portfolio managers of the fund since inception except for Mr. Shedroff who has been a portfolio manager of the fund since 2021.

OTHER IMPORTANT INFORMATION REGARDING FUND SHARES

For important information about purchase and sale of fund shares, tax information, and payments to broker-dealers and other financial representatives, please see the "Summary of Other Important Information Regarding Fund Shares" section on page 41 of this Prospectus.

CREDIT SUISSE MANAGED FUTURES STRATEGY FUND – SUMMARY

INVESTMENT OBJECTIVE

FEES AND FUND EXPENSES

  ¹​  Purchases of shares of $1 million or more may be subject to a 1% deferred sales charge on redemptions within 12 months of purchase.

  ²​  1.00% during the first year.

  ³​  The fund invests in Credit Suisse Cayman Managed Futures Strategy Fund, Ltd. (the "Subsidiary"), a wholly-owned subsidiary of the fund organized under the laws of the Cayman Islands. "Other expenses" include expenses of both the fund and the Subsidiary.

  ⁴​  Acquired Fund Fees and Expenses reflect the expenses incurred indirectly by the Fund as a result of the Fund's investments in underlying money market mutual funds, exchange-traded funds or other pooled investment vehicles.

  ⁵​  Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.55% of the fund's average daily net assets for Class A shares, 2.30% of the fund's average daily net assets for Class C shares and 1.30% of the fund's average daily net assets for Class I shares at least through February 28, 2025. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously waived and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursement must be paid at a date not more than thirty-six months following the applicable month during which such fees were waived or expenses were paid by Credit Suisse and the reimbursement does not cause the applicable class's aggregate expenses, on an annualized basis to exceed either (i) the applicable expense limited in effect at the time such fees were waived or such expenses were paid by Credit Suisse or (ii) the applicable expense limitation in effect at the time of such reimbursement. This contract may not be terminated before February 28, 2025.

EXAMPLE

PORTFOLIO TURNOVER

PRINCIPAL INVESTMENT STRATEGIES

PRINCIPAL RISKS OF INVESTING IN THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time.

The fund is not a complete investment program and should only form a part of a diversified portfolio. Investors in the fund should be willing to assume the risks of potentially significant short-term share price fluctuations.

Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

COMMODITY EXPOSURE RISKS

The fund's and the Subsidiary's investments in commodity-linked derivative instruments may subject the fund to greater volatility than investments in traditional securities, particularly if the investments involve leverage. The value of commodity-linked derivatives instruments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or sectors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments.

Use of leveraged commodity-linked derivatives creates an opportunity for increased return but, at the same time, creates the possibility for greater loss (including the likelihood of greater volatility of the fund's net asset value), and there can be no assurance that the fund's use of leverage will be successful.

CORRELATION RISK

Changes in the value of a hedging instrument may not match those of the investment being hedged. In addition, certain of the fund's commodity-linked derivative investments may result in the fund's performance diverging from the BCOM Index, perhaps materially. For example, a structured note can be structured to limit the loss or the gain on the investment, which would result in the fund not participating in declines or increases in the BCOM Index that exceed the limits.

COUNTERPARTY RISK

A fund will be exposed to the credit of the counterparties to over-the-counter ("OTC") derivative contracts and repurchase agreements and their ability to satisfy the terms of the agreements, which exposes the fund to the risk that the counterparties may default on their obligations to perform under the agreements. In the event of a bankruptcy or insolvency of a counterparty, the fund could experience delays in liquidating the positions and significant losses, including declines in the value of its investment during the period in which the fund seeks to enforce its rights, inability to realize any gains on its investment during such period, loss of collateral and fees and expenses incurred in enforcing its rights.

CREDIT RISK

The issuer of a debt instrument, the borrower of a loan or the counterparty to a contract (including derivatives contracts) may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer.

CURRENCY RISK

Currency risk is the risk that changes in currency exchange rates will negatively affect securities or instruments denominated in, and/or payments received in, foreign currencies. Adverse changes in currency exchange rates (relative to the U.S. dollar) may erode or reverse any potential gains from the fund's investments in financial instruments with underlying securities or instruments denominated in a foreign currency or may widen existing losses.

DERIVATIVES RISK

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The fund typically uses derivatives as a substitute for taking a position in the underlying asset. The fund also may use derivatives for leverage. The fund's use of derivative instruments, particularly commodity-linked derivatives, involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this Prospectus, such as commodity exposure risks, correlation risk, counterparty risk, credit risk, currency risk, equity exposure risk, fixed income risk, illiquidity risk, interest rate risk, leveraging risk, market risk and regulatory risk. Also, suitable derivative transactions may not be available in all circumstances.

EQUITY EXPOSURE RISK

The fund may obtain exposure to equity securities. Equity security prices have historically risen and fallen in periodic cycles. U.S. and foreign equity markets have experienced periods of substantial price volatility in the past and may do so again in the future.

FIXED INCOME RISK

The market value of fixed income investments, and financial instruments related to those fixed income investments, will change in response to interest rate changes and other factors, such as changes in the effective maturities and credit ratings of fixed income investments. During periods of falling interest rates, the values of outstanding fixed income securities and related financial instruments generally rise. Conversely, during periods of rising interest rates, the values of such securities and related financial instruments generally decline. Fixed income investments are also subject to credit risk.

FOREIGN SECURITIES RISK

Investing outside the U.S. carries additional risks that include:

◼  Currency Risk See "Currency Risk" above.

◼  Information Risk Key information about an issuer, security or market may be inaccurate or unavailable.

◼  Political Risk Foreign governments may expropriate assets, impose capital or currency controls, and/or sanctions impose punitive taxes, or nationalize a company or industry. Any of these actions could have a severe effect on security prices and impair the fund's ability to bring its capital or income back to the U.S. Other political risks include economic policy changes, social and political instability, military action and war, such as the war between Russia and Ukraine and the conflict between Israel and Hamas.

FORWARDS RISK

Forwards are not exchange-traded and therefore no clearinghouse or exchange stands ready to meet the obligations of the contracts. Thus, the fund faces the risk that its counterparties may not perform their obligations. Forward contracts are not regulated by the Commodity Futures Trading Commission (the "CFTC") and therefore, the fund will not receive any benefit of CFTC regulation when trading forwards.

FUTURES CONTRACTS RISK

The risks associated with the fund's use of futures contracts and swaps and structured notes that reference the price of futures contracts include the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying reference asset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts; and (iii) if the fund has insufficient cash to meet margin requirements, the fund may need to sell other investments, including at disadvantageous times.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an investment. With bonds and other debt instruments, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The Federal Reserve has raised the federal funds rate as part of its efforts to address rising inflation. If interests rates continue to increase in the near future, this could adversely affect the price and liquidity of fund investments. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest rates on the instrument's value. In periods of market volatility, the market values of fixed income securities may be more sensitive to changes in interest rates.

LEVERAGING RISK

The fund may invest in certain derivatives that provide leveraged exposure. The fund's investment in these instruments generally requires a small investment relative to the amount of investment exposure assumed. As a result, such investments may cause the fund to lose more than the amount it invested in those instruments. The net asset value of the fund when employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the portfolio to pay interest.

MANAGER/MODEL RISK

If a fund's portfolio managers make poor investment decisions, it will negatively affect the fund's performance. The fund also bears the risk that the proprietary model used by the portfolio managers will not be successful in identifying investments that will help the fund achieve its investment objective, causing the fund to underperform its benchmark or other funds with a similar investment objective.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sector of the economy, or the market as a whole. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, natural disasters, recessions, or other events could have a significant impact on the fund and its investments. Market risk is common to most investments – including stocks, bonds and commodities – and the mutual funds that invest in them. The performance of "value" stocks and "growth" stocks may rise or decline under varying market conditions – for example, value stocks may perform well under circumstances in which growth stocks in general have fallen.

Bonds and other fixed income securities generally involve less market risk than stocks and commodities. However, the risk of bonds can vary significantly depending upon factors such as the issuer's creditworthiness and a bond's maturity. The bonds of some companies may be riskier than the stocks of others.

MODEL AND STYLE RISK

Certain funds bear the risk that the underlying index's proprietary quantitative methodology will not be successful in identifying price trends in each of the asset classes to which its underlying index provides exposure. Further, the index's proprietary quantitative methodology may incorrectly identify price trends and these misidentified opportunities may lead to substantial losses. In addition, there may be periods when investing based on price trends is out of favor, and during which the investment performance of a fund or index using a trend strategy may underperform funds or indices using other investment approaches.

NON-DIVERSIFIED STATUS

The fund is considered a non-diversified investment company under the 1940 Act, and is permitted to invest a greater proportion of its assets in the securities of a smaller number of issuers than a diversified fund. As a result, the fund may be subject to greater volatility with respect to its portfolio securities than a fund that is diversified.

OPTIONS RISK

A decision as to whether, when and how to use options involves the exercise of skill and judgment, and even a well-conceived and well-executed options program may be adversely affected by market behavior or unexpected events. Successful options strategies may require the anticipation of future movements in securities prices, interest rates and other economic factors. No assurances can be given that Credit Suisse's judgment in this respect will be correct. When the fund purchases options, it risks losing all or part of the cash paid for the options. Because option premiums paid or received by the fund indirectly are small in relation to the market value of the investments underlying the options, buying and selling put and call options can be more speculative than investing directly in securities.

PORTFOLIO TURNOVER RISK

The fund expects to engage in frequent trading of derivatives. Active and frequent trading may lead to the realization and distribution to shareholders of higher short-term capital gains, which would increase their tax liability. Frequent trading also increases transaction costs, which could detract from the fund's performance.

REPURCHASE AGREEMENTS RISK

Repurchase agreements could involve certain risks in the event of default or insolvency of the seller, including losses and possible delays or restrictions upon the fund's ability to dispose of the underlying securities. To the extent that, in the meantime, the value of the securities that the fund has purchased has decreased, the fund could experience a loss. The fund will be exposed to the credit of the counterparties to repurchase agreements and their ability to satisfy the terms of the agreements, which exposes the fund to the risk that the counterparties may default on their obligations to perform under the agreements.

SHORT POSITION RISK

The fund or the Subsidiary may enter into a short position through a futures contract or swap agreement or by selling a security short. Taking short positions involves leverage of the fund's or the Subsidiary's assets and presents various risks. If the price of the asset, instrument or market on which the fund or the Subsidiary has taken a short position increases, then the fund or the Subsidiary will incur a loss equal to the increase in price from the time that the short position was entered into plus any premiums and interest paid to a third party in connection with the short sale. Therefore, taking short positions involves the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. The fund's or the Subsidiary's loss on a short sale could theoretically be unlimited in a case where the fund or the Subsidiary, as the case may be, is unable, for whatever reason, to close out its short position. The fund's risk of loss with respect to short sales may be significant, as the fund may have a substantial amount of short positions in its portfolio.

SPECULATIVE EXPOSURE RISK

Gains or losses from speculative positions in a derivative may be much greater than the derivative's original cost. For example, potential losses from swaps and speculative short sales are unlimited.

SUBSIDIARY RISK

By investing in the Subsidiary, the fund is indirectly exposed to the risks associated with the Subsidiary's investments. The derivatives and other investments held by the Subsidiary are generally similar to those that are permitted to be held by the fund and are subject to the same risks that apply to similar investments if held directly by

the fund. These risks are described elsewhere in this Prospectus. There can be no assurance that the investment objective of the Subsidiary will be achieved.

The Subsidiary is not registered under the 1940 Act, and, unless otherwise noted in this Prospectus, is not subject to all the investor protections of the 1940 Act. However, the fund wholly owns and controls the Subsidiary, and the fund and the Subsidiary are both managed by Credit Suisse, making it unlikely that the Subsidiary will take action contrary to the interests of the fund and its shareholders. The fund's Board of Trustees has oversight responsibility for the investment activities of the fund, including its investment in the Subsidiary, and the fund's role as sole shareholder of the Subsidiary. The Subsidiary will be subject to the same investment restrictions and limitations, and follow the same compliance policies and procedures as the fund.

Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the fund and/or the Subsidiary to continue to operate as it does currently and could adversely affect the fund.

SWAP AGREEMENTS RISK

Swap agreements involve the risk that the party with whom the fund has entered into the swap will default on its obligation to pay the fund and the risk that the fund will not be able to meet its obligations to pay the other party to the agreement.

TAX RISK

In order to qualify as a Regulated Investment Company (a "RIC") under the Internal Revenue Code of 1986, as amended, the fund must meet certain requirements regarding the source of its income, the diversification of its assets and the distribution of its income. The Internal Revenue Service has issued a ruling that income realized directly from certain types of commodity-linked derivatives would not be qualifying income. As a result, the fund's ability to realize income from direct investments in such commodity-linked derivatives as part of its investment strategy would be limited to a maximum of 10% of its gross income. To comply with the ruling, the fund seeks to gain exposure to the commodity markets primarily through investments in the Subsidiary, which invests in commodity-linked swaps, commodity futures and other derivatives, and directly through investments in commodity-linked notes. If the fund fails to qualify as a RIC, the fund will be subject to federal income tax on its net income at regular corporate rates (without reduction for distributions to shareholders). When distributed, that income also would be taxable to shareholders as an ordinary dividend to the extent attributable to the fund's earnings and profits. If the fund were to fail to qualify as a RIC and became subject to federal income tax, shareholders of the fund would be subject to diminished returns. The fund anticipates treating income and gain from the Subsidiary and from commodity-linked notes as qualifying income.

U.S. GOVERNMENT SECURITIES RISK

Obligations of U.S. government agencies and authorities are supported by varying degrees of credit but generally are not backed by the full faith and credit of the U.S. government. No assurance can be given that the U.S. government will provide financial support to its agencies and authorities if it is not obligated by law to do so.

PERFORMANCE

AVERAGE ANNUAL TOTAL RETURNS

PORTFOLIO MANAGEMENT

Investment manager: Credit Suisse Asset Management, LLC

Portfolio managers: The Quantitative Investment Strategies group ("QIS") is responsible for the day-to-day portfolio management of the Fund. Yung-Shin Kung, a Managing Director of Credit Suisse, is the lead portfolio manager of the team and has been managing the Fund since November 2015.

OTHER IMPORTANT INFORMATION REGARDING FUND SHARES

For important information about purchase and sale of fund shares, tax information, and payments to broker-dealers and other financial representatives, please see the "Summary of Other Important Information Regarding Fund Shares" section on page 41 of this Prospectus.

CREDIT SUISSE MULTIALTERNATIVE STRATEGY FUND – SUMMARY

INVESTMENT OBJECTIVE

FEES AND FUND EXPENSES

  ¹​  Purchases of shares of $1 million or more may be subject to a 1% deferred sales charge on redemptions within 12 months of purchase.

  ²​  The fund may invest in Credit Suisse Cayman Multialternative Strategy Fund, Ltd. (the "Subsidiary"), a wholly-owned subsidiary of the fund organized under the laws of the Cayman Islands. "Other expenses" include expenses of both the fund and the Subsidiary.

  ³​  The "Total annual fund operating expenses" in the table above do not correlate to the ratio of expenses to average net assets found within the Financial Highlights section of this Prospectus, which reflects the operating expenses of the fund and does not include Acquired Fund Fees and Expenses.

  ⁴​  Acquired Fund Fees and Expenses reflect the expenses incurred indirectly by the Fund as a result of the Fund's investments in underlying money market mutual funds, exchange-traded funds or other pooled investment vehicles.

  ⁵​  Credit Suisse Opportunity Funds (the "Trust") and Credit Suisse Asset Management, LLC ("Credit Suisse") have entered into a written contract limiting operating expenses to 1.10% of the fund's average daily net assets for Class A shares and 0.85% of the fund's average daily net assets for Class I shares at least through February 28, 2025. This limit excludes certain expenses, including interest charges on fund borrowings, taxes, brokerage commissions, dealer spreads and other transaction charges, expenditures that are capitalized in accordance with generally accepted accounting principles, acquired fund fees and expenses, short sale dividends, and extraordinary expenses (e.g., litigation and indemnification and any other costs and expenses that may be approved by the Board of Trustees). The Trust is authorized to reimburse Credit Suisse for management fees previously waived and/or for expenses previously paid by Credit Suisse, provided, however, that any reimbursement must be paid at a date not more than thirty-six months following the applicable month during which such fees were waived or expenses were paid by Credit Suisse and the reimbursement does not cause the applicable class's aggregate expenses, on an annualized basis to exceed either (i) the applicable expense limited in effect at the time such fees were waived or such expenses were paid by Credit Suisse or (ii) the applicable expense limitation in effect at the time of such reimbursement. This contract may not be terminated before February 28, 2025.

EXAMPLE

PORTFOLIO TURNOVER

PRINCIPAL INVESTMENT STRATEGIES

PRINCIPAL RISKS OF INVESTING IN THE FUND

A WORD ABOUT RISK

All investments involve some level of risk. Simply defined, risk is the possibility that you will lose money or not make money.

Principal risk factors for the fund are discussed below. Before you invest, please make sure you understand the risks that apply to the fund. As with any mutual fund, you could lose money over any period of time.

Investments in the fund are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

ARBITRAGE OR FUNDAMENTAL RISK

Employing arbitrage and alternative strategies has the risk that anticipated opportunities do not play out as planned, resulting in potentially reduced returns or losses to the fund as it unwinds failed trades.

BELOW INVESTMENT GRADE SECURITIES RISK

Below investment grade securities (commonly referred to as "junk bonds") are regarded as being predominantly speculative as to the issuer's ability to make payments of principal and interest. Investment in such securities involves substantial risk. Issuers of below investment grade securities may be highly leveraged and may not have available to them more traditional methods of financing. Therefore, the risks associated with acquiring the securities of such issuers generally are greater than is the case with higher-rated securities.

COMMODITY EXPOSURE RISKS

The fund's and the Subsidiary's investments in commodity-linked derivative instruments may subject the fund to greater volatility than investments in traditional securities, particularly if the investments involve leverage. The value of commodity-linked derivative instruments may be affected by changes in overall market movements, commodity index volatility, changes in interest rates, or factors affecting a particular industry or commodity, such as drought, floods, weather, livestock disease, embargoes, tariffs and international economic, political and regulatory developments.

Use of leveraged commodity-linked derivatives creates an opportunity for increased return but, at the same time, creates the possibility for greater loss (including the likelihood of greater volatility of the fund's net asset value), and there can be no assurance that the fund's use of leverage will be successful.

CONVERTIBLE SECURITIES RISK

The market value of a convertible security performs like that of a regular debt security; that is, if market interest rates rise, the value of a convertible security usually falls. In addition, convertible securities are subject to the risk that the issuer will not be able to pay interest or dividends when due, and their market value may change based on changes in the issuer's credit rating or the market's perception of the issuer's creditworthiness. Since it derives a portion of its value from the common stock into which it may be converted, a convertible security is also subject to the same types of market and issuer risks that apply to the underlying common stock. The fund, as a holder of convertible bonds, may at times be allocated phantom taxable income from bond issuers, potentially retroactively or otherwise without notice.

CORRELATION RISK

Changes in the value of a hedging instrument may not match those of the investment being hedged. In addition, certain of the fund's commodity-linked derivative investments may result in the fund's performance diverging from the BCOM Index, perhaps materially. For example, a structured note can be structured to limit the loss or the gain on the investment, which would result in the fund not participating in declines or increases in the BCOM Index that exceed the limits.

COUNTERPARTY RISK

A fund will be exposed to the credit of the counterparties to OTC derivative contracts and repurchase agreements and their ability to satisfy the terms of the agreements, which exposes the fund to the risk that the counterparties may default on their obligations to perform under the agreements. In the event of a bankruptcy or insolvency of a counterparty, the fund could experience delays in liquidating the positions and significant losses, including declines in the value of its investment during the period in which the fund seeks to enforce its rights, inability to realize any gains on its investment during such period, loss of collateral and fees and expenses incurred in enforcing its rights.

CREDIT RISK

The issuer of a security or the counterparty to a contract, including derivatives contracts, may default or otherwise become unable to honor a financial obligation. Changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness also may affect the value of the fund's investment in that issuer. Non-investment grade securities carry a higher risk of default and should be considered speculative.

DERIVATIVES RISK

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The fund typically uses derivatives as a substitute for taking a position in the underlying asset and/or as part of a strategy designed to reduce exposure to other risks, such as interest rate or currency risk. The fund also may use derivatives for leverage. The fund's use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this Prospectus, such as commodity exposure risks, correlation risk, counterparty risk, credit risk, illiquidity risk, interest rate risk, leveraging risk, market risk and regulatory risk. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that the fund will engage in these transactions to reduce exposure to other risks when that would be beneficial.

EQUITY EXPOSURE RISK

The fund may obtain exposure to equity securities. Equity security prices have historically risen and fallen in periodic cycles. U.S. and foreign equity markets have experienced periods of substantial price volatility in the past and may do so again in the future.

FIXED INCOME RISK

The market value of fixed income investments, and financial instruments related to those fixed income investments, will change in response to interest rate changes and other factors, such as changes in the effective maturities and credit ratings of fixed income investments. During periods of falling interest rates, the values of outstanding fixed income securities and related financial instruments generally rise. Conversely, during periods of rising interest rates, the values of such securities and related financial instruments generally decline. Fixed income investments are also subject to credit risk.

FOREIGN SECURITIES RISK

Investing outside the U.S. carries additional risks that include:

◼  Currency Risk Fluctuations in exchange rates between the U.S. dollar and foreign currencies may negatively affect an investment. Adverse changes in exchange rates may erode or reverse any gains produced by foreign-currency-denominated investments and may widen any losses. The fund may, but is not required to, seek to reduce currency risk by hedging part or all of its exposure to various foreign currencies.

◼  Emerging Markets Risk The risks of investing in foreign securities are increased in connection with investments in emerging markets. Emerging markets are countries generally considered to be relatively less developed or industrialized. Emerging markets often face economic problems that could subject the fund to increased volatility or

substantial declines in value, and emerging markets may experience periods of market illiquidity. Deficiencies in regulatory oversight, market infrastructure, shareholder protections and company laws and differences in regulatory, accounting, auditing, and financial reporting and recordkeeping standards could expose the fund to risks beyond those generally encountered in developed countries. In addition, profound social changes and business practices that depart from norms in developed countries' economies have hindered the orderly growth of emerging economies and their markets in the past and have caused instability. High levels of debt tend to make emerging economies heavily reliant on foreign capital and vulnerable to capital flight. Countries in emerging markets are also more likely to experience high levels of inflation, deflation, currency devaluation or unemployment, which could hurt their economies and securities markets. For these and other reasons, investments in emerging markets are often considered speculative.

◼  Information Risk Key information about an issuer, security or market may be inaccurate or unavailable.

◼  Political Risk Foreign governments may expropriate assets, impose capital or currency controls, and/or sanctions impose punitive taxes, or nationalize a company or industry. Any of these actions could have a severe effect on security prices and impair the fund's ability to bring its capital or income back to the U.S. Other political risks include economic policy changes, social and political instability, military action and war, such as the war between Russia and Ukraine and the conflict between Israel and Hamas.

FORWARDS RISK

Forwards are not exchange-traded and therefore no clearinghouse or exchange stands ready to meet the obligations of the contracts. Thus, the fund faces the risk that its counterparties may not perform their obligations. Forward contracts also are not regulated by the Commodity Futures Trading Commission (the "CFTC") and therefore the fund will not receive any benefit of CFTC regulation when trading forwards.

FUTURES CONTRACTS RISK

The risks associated with the fund's use of futures contracts include the risk that: (i) changes in the price of a futures contract may not always track the changes in market value of the underlying reference asset; (ii) trading restrictions or limitations may be imposed by an exchange, and government regulations may restrict trading in futures contracts; and (iii) if the fund has insufficient cash to meet margin requirements, the fund may need to sell other investments, including at disadvantageous times.

HEDGED EXPOSURE RISK

A fund's hedging activities could multiply losses generated by a derivative used for hedging purposes. Such losses should be substantially offset by gains on the hedged investment. However, while hedging can reduce or eliminate losses, it can also reduce or eliminate gains.

INTEREST RATE RISK

Changes in interest rates may cause a decline in the market value of an investment. With bonds and other fixed income securities, a rise in interest rates typically causes a fall in values, while a fall in interest rates typically causes a rise in values. The Federal Reserve has raised the federal funds rate as part of its efforts to address rising inflation. If interests rates continue to increase in the near future, this could adversely affect the price and liquidity of fund investments. Generally, the longer the maturity or duration of a debt instrument, the greater the impact of a change in interest rates on the instrument's value. In periods of market volatility, the market values of fixed income securities may be more sensitive to changes in interest rates.

LEVERAGING RISK

The fund may invest in certain derivatives that provide leveraged exposure. The fund's investment in these instruments generally requires a small investment relative to the amount of investment exposure assumed. As a result, such investments may cause the fund to lose more than the amount it invested in those instruments. The net asset value of the fund when employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the portfolio to pay interest.

MANAGER/MODEL RISK

If the fund's portfolio managers make poor investment decisions, it will negatively affect the fund's performance. The fund also bears the risk that the proprietary model used by the portfolio managers will not be successful in identifying

investments that will help the fund achieve its investment objective, causing the fund to underperform its benchmark or other funds with a similar investment objective.

MARKET RISK

The market value of an instrument may fluctuate, sometimes rapidly and unpredictably. These fluctuations, which are often referred to as "volatility," may cause an instrument to be worth less than it was worth at an earlier time. Market risk may affect a single issuer, industry, commodity, sector of the economy, or the market as a whole. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, natural disasters, recessions, or other events could have a significant impact on the fund and its investments. Market risk is common to most investments – including stocks, bonds and commodities – and the mutual funds that invest in them. The performance of "value" stocks and "growth" stocks may rise or decline under varying market conditions – for example, value stocks may perform well under circumstances in which growth stocks in general have fallen.

Bonds and other fixed income securities generally involve less market risk than stocks and commodities. However, the risk of bonds can vary significantly depending upon factors such as the issuer's creditworthiness and a bond's maturity. The bonds of some companies may be riskier than the stocks of others.

NON-DIVERSIFIED STATUS

The fund is considered a non-diversified investment company under the Investment Company Act of 1940, as amended (the "1940 Act"), and is permitted to invest a greater proportion of its assets in the securities of a smaller number of issuers than a diversified fund. As a result, the fund may be subject to greater volatility with respect to its portfolio securities than a fund that is diversified.

OPTIONS RISK

A decision as to whether, when and how to use options involves the exercise of skill and judgment, and even a well-conceived and well-executed options program may be adversely affected by market behavior or unexpected events. Successful options strategies may require the anticipation of future movements in securities prices, interest rates and other economic factors. No assurances can be given that Credit Suisse's judgment in this respect will be correct. When the fund purchases options, it risks losing all or part of the cash paid for the options. Because option premiums paid or received by the fund indirectly are small in relation to the market value of the investments underlying the options, buying and selling put and call options can be more speculative than investing directly in securities.

PORTFOLIO TURNOVER RISK

Active and frequent trading may lead to the realization and distribution to shareholders of higher short-term capital gains, which would increase their tax liability. Frequent trading also increases transaction costs, which could detract from the fund's performance.

RISKS OF INVESTING IN OTHER FUNDS

Other mutual funds and ETFs are subject to investment advisory and other expenses. If the fund invests in other mutual funds or ETFs, the cost of investing in the fund may be higher than other funds that invest only directly in individual securities. Shareholders will indirectly bear fees and expenses charged by the other mutual funds and ETFs in addition to the fund's direct fees and expenses. Other mutual funds and ETFs are subject to specific risks, depending on the nature of the mutual fund or ETF.

Most ETFs are investment companies whose shares are purchased and sold on a securities exchange. An ETF represents a portfolio of securities designed to track a particular market segment or index. An investment in an ETF generally presents the same primary risks as an investment in a conventional fund (i.e., one that is not exchange-traded) that has the same investment objectives, strategies and policies. In addition, an ETF may fail to accurately track the market segment or index that underlies its investment objective. The price of an ETF can fluctuate, and the fund could lose money investing in an ETF.

Credit Suisse serves as the adviser to other mutual funds in which the fund may invest. It is possible that a conflict of interest among the fund and the other Credit Suisse Funds could affect how Credit Suisse fulfills its fiduciary duties to the fund and the other Credit Suisse Funds.

SHORT POSITION RISK

The fund may enter into a short position through a futures contract or swap agreement or by selling a security short. Taking short positions involves leverage of the fund's assets and presents various risks. If the price of the asset,

instrument or market on which the fund has taken a short position increases, then the fund will incur a loss equal to the increase in price from the time that the short position was entered into plus any premiums and interest paid to a third party in connection with the short sale. Therefore, taking short positions involves the risk that losses may be exaggerated, potentially losing more money than the actual cost of the investment. The fund's loss on a short sale could theoretically be unlimited in a case where the fund is unable, for whatever reason, to close out its short position.

SMALL- AND MID-CAP STOCK RISK

The fund may invest in small- and mid-cap stocks. Stocks of small-cap companies, and to a lesser extent, mid-cap companies, may be more volatile than, and not as readily marketable as, those of larger companies.

SPECULATIVE EXPOSURE RISK

Gains or losses from speculative positions in a derivative may be much greater than the derivative's original cost. For example, potential losses from commodity-linked swap agreements and from writing uncovered call options are unlimited.

SUBSIDIARY RISK

By investing in the Subsidiary, the fund is exposed indirectly to the risks associated with the Subsidiary's investments. The derivatives and other investments held by the Subsidiary are generally similar to those that are permitted to be held by the fund and are subject to the same risks that apply to similar investments if held directly by the fund. These risks are described elsewhere in this Prospectus. There can be no assurance that the investment objective of the Subsidiary will be achieved.

The Subsidiary is not registered under the 1940 Act, and, unless otherwise noted in this Prospectus, is not subject to all the investor protections of the 1940 Act. However, the fund wholly owns and controls the Subsidiary, and the fund and the Subsidiary are both managed by Credit Suisse, making it unlikely that the Subsidiary will take action contrary to the interests of the fund and its shareholders. The fund's Board of Trustees has oversight responsibility for the investment activities of the fund, including its investment in the Subsidiary, and the fund's role as sole shareholder of the Subsidiary. The Subsidiary will be subject to the same investment restrictions and limitations, and follow the same compliance policies and procedures, as the fund.

Changes in the laws of the United States and/or the Cayman Islands could result in the inability of the fund and/or the Subsidiary to continue to operate as it does currently and could adversely affect the fund.

SWAP AGREEMENTS RISK

Swap agreements involve the risk that the party with whom the fund has entered into the swap will default on its obligation to pay the fund and the risk that the fund will not be able to meet its obligations to pay the other party to the agreement.

TAX RISK

In order to qualify as a Regulated Investment Company (a "RIC") under the Internal Revenue Code of 1986, as amended, the fund must meet certain requirements regarding the source of its income, the diversification of its assets and the distribution of its income. The Internal Revenue Service has issued a ruling that income realized directly from certain types of commodity-linked derivatives would not be qualifying income. As a result, the fund's ability to realize income from investments in such commodity-linked derivatives as part of its investment strategy would be limited to a maximum of 10% of its gross income. To comply with the ruling, the fund seeks to gain exposure to the commodity markets primarily through investments in the Subsidiary, which invests in commodity-linked swaps, commodity futures and other derivatives, and directly through investments in commodity-linked notes. If the fund fails to qualify as a RIC, the fund will be subject to federal income tax on its net income at regular corporate rates (without reduction for distributions to shareholders). When distributed, that income also would be taxable to shareholders as an ordinary dividend to the extent attributable to the fund's earnings and profits. If the fund were to fail to qualify as a RIC and became subject to federal income tax, shareholders of the fund would be subject to diminished returns. The fund anticipates treating income and gain from the Subsidiary and from commodity-linked notes as qualifying income.

PERFORMANCE

AVERAGE ANNUAL TOTAL RETURNS

PORTFOLIO MANAGEMENT

Investment manager: Credit Suisse Asset Management, LLC

Portfolio managers: The Quantitative Investment Strategies group ("QIS") is responsible for the day-to-day portfolio management of the Fund. Yung-Shin Kung, a Managing Director of Credit Suisse, is the lead portfolio manager of the team and has been managing the Fund since November 2015.

OTHER IMPORTANT INFORMATION REGARDING FUND SHARES

For important information about purchase and sale of fund shares, tax information, and payments to broker-dealers and other financial representatives, please see the "Summary of Other Important Information Regarding Fund Shares" section on page 41 of this Prospectus.