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DWS Money Market Prime Series

Summary Prospectus | December 1, 2025

Class/Ticker

DWS Cash Investment Trust Class

DOAXX

DOCXX

DOSXX

Before you invest, you may want to review the fund’s prospectus, which contains more information about the fund and its risks. You can find the fund’s prospectus, reports to shareholders, Statement of Additional Information (SAI) and other information about the fund online at dws.com/moneypros. You can also get this information at no cost by e-mailing a request to service@dws.com, calling (800) 728-3337 or asking your financial representative. The Prospectus and SAI, both dated December 1, 2025, as may be revised or supplemented from time to time, are incorporated by reference into this Summary Prospectus.

Investment Objective

The fund seeks maximum current income to the extent consistent with stability of principal.

Fees and Expenses

These are the fees and expenses you may pay when you buy, hold and sell shares. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. More information about discounts and waivers is available from your financial representative and in Choosing a Share Class in the prospectus (p. 15), Sales Charge Waivers and Discounts Available Through Intermediaries in the prospectus (Appendix B, p. 34) and Purchase and Redemption of Shares in the fund’s SAI (p. II-15).

SHAREHOLDER FEES (paid directly from your investment)

	A	C	S
Maximum deferred sales charge (load), as % of redemption proceeds	None	1.00	None
Account Maintenance Fee (annually, for fund account balances below $10,000 and subject to certain exceptions)	$20	$20	$20

ANNUAL FUND OPERATING EXPENSES
(expenses that you pay each year as a % of the value of your investment)

	A	C	S
Management fee	0.32	0.32	0.32
Distribution/service (12b-1) fees	0.25	1.00	None
Other expenses1	0.30	0.27	0.34
Total annual fund operating expenses	0.87	1.59	0.66
Fee waiver/expense reimbursement	0.02	0.00	0.09
Total annual fund operating expenses after fee waiver/expense reimbursement	0.85	1.59	0.57

“Other expenses” are restated to exclude fees related to proxy expenses. “Other expenses” would have been 0.31%, 0.28% and 0.35% for Class A, Class C and Class S, respectively, had proxy expenses been included.

The Advisor has contractually agreed through November 30, 2026 to waive its fees and/or reimburse fund expenses to the extent necessary to maintain the fund's total annual operating expenses (excluding certain expenses such as extraordinary expenses, taxes, brokerage and interest expenses) at ratios no higher than 0.85% and 0.57% for Class A and Class S, respectively. The agreement may only be terminated with the consent of the fund's Board.

EXAMPLE

This Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund's operating expenses (including one year of capped expenses in each period for Class A and Class S) remain the same. Class C shares generally convert automatically to Class A shares after 8 years. The information presented in the Example for Class C reflects the conversion of Class C shares to Class A shares after 8 years. See “Class C Shares” in the “Choosing a Share Class” section of the prospectus for more information. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Years	A	C	S
1	$87	$262	$58
3	276	502	202
5	480	866	359
10	1,071	1,696	814

You would pay the following expenses if you did not redeem your shares:

Years	A	C	S
1	$87	$162	$58
3	276	502	202
5	480	866	359
10	1,071	1,696	814

Principal Investment Strategies

Main investments. The fund is a money market fund that is managed in accordance with federal regulations which govern the quality, maturity, diversity and liquidity of instruments in which a money market fund may invest.

The fund invests in high quality, short-term, US dollar denominated money market instruments, including obligations of US and foreign banks, corporate obligations, US government securities, municipal securities, repurchase agreements and asset-backed securities, paying a fixed, variable or floating interest rate.

Under normal market conditions, the fund will invest more than 25% of its total assets in the obligations of banks and other financial institutions that satisfy the fund's eligibility requirements.

The fund may invest up to 10% of its total assets in other money market funds.

Management process. Working in consultation with portfolio management, a credit team screens potential securities and develops a list of those that the fund may buy. Portfolio management, looking for attractive yield and weighing considerations such as credit quality, economic outlooks and possible interest rate movements, then decides which securities on this list to buy.

Main Risks

There are several risk factors that could reduce the yield you get from the fund, cause the fund’s performance to trail that of other investments, or cause you to lose money.

Money market fund risk. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a discretionary liquidity fee (not to exceed 2%) upon redemption of shares if the Advisor determines a liquidity fee is in the fund's best interests. The Advisor may impose such a fee in times of market stress, impaired liquidity of the fund's investments or in other circumstances. A liquidity fee would reduce the amount a shareholder receives upon redemption of shares. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund’s sponsor has no legal obligation to provide financial support to the fund, and you should not expect that the sponsor will provide financial support to the fund at any time.

Market risk. The market value of the securities in which the fund invests may be impacted by the prospects of individual issuers, particular sectors or governments and/or general economic conditions throughout the world due to increasingly interconnected global economies and financial markets.

Market disruption risk. Economies and financial markets throughout the world have become increasingly interconnected, which has increased the likelihood that events or conditions in one country or region will adversely impact markets or issuers in other countries or regions. This includes reliance on global supply chains that are susceptible to disruptions resulting from, among other things, war and other armed conflicts, tariffs, extreme weather events, and natural disasters. Such supply chain disruptions can lead to, and have led to, economic and market disruptions that have far-reaching effects on financial markets worldwide. The value of the fund’s investments may be negatively affected by adverse changes in overall economic or market conditions, such as the level of economic activity and productivity, unemployment and labor force participation rates, inflation or deflation (and expectations for inflation or deflation), interest rates, demand and supply for particular products or resources including labor, debt levels and credit ratings, and trade policies, among other factors. Such adverse conditions may contribute to an overall economic contraction across entire economies or markets, which may negatively impact the profitability of issuers operating in those economies or markets. In addition, geopolitical and other globally interconnected occurrences, including war, terrorism, economic uncertainty or financial crises, contagion, tariffs and trade disputes, government debt crises (including defaults or downgrades) or uncertainty about government debt payments, government shutdowns, public health crises, natural disasters, supply chain disruptions, climate change and related events or conditions, have led, and in the future may lead, to disruptions in the US and world economies and markets, which may increase financial market volatility and have significant adverse direct or indirect effects on the fund and its investments. Adverse market conditions or disruptions could cause the fund to lose money, experience significant redemptions, and encounter operational difficulties. Although multiple asset classes may be affected by adverse market conditions or a particular market disruption, the duration and effects may not be the same for all types of assets.

Current military and other armed conflicts in various geographic regions, including those in Europe and the Middle East, among others, can lead to, and have led to, economic and market disruptions, which may not be limited to the geographic region in which the conflict is occurring. Such conflicts can also result, and have resulted in some cases, in sanctions being levied by the United States, the European Union and/or other countries against countries or other actors involved in the conflict. In addition, such conflicts and related sanctions can adversely

DWS Money Market Prime Series

Summary Prospectus December 1, 2025

affect regional and global energy, commodities, financial and other markets and thus could affect the value of the fund's investments. The extent and duration of any military or other armed conflict, related sanctions and resulting economic and market disruptions are impossible to predict, but could be substantial.

Other market disruption events include pandemic spread of viruses, such as the novel coronavirus known as COVID-19, which have caused significant uncertainty, market volatility, decreased economic and other activity, increased government activity, including economic stimulus measures, and supply chain disruptions, and may adversely affect the fund and its investments.

In addition, markets are becoming increasingly susceptible to disruption events resulting from the use of new and emerging technologies to engage in cyber-attacks or to take over the Web sites and/or social media accounts of companies, governmental entities or public officials, or to otherwise pose as or impersonate such, which then may be used to disseminate false or misleading information that can cause volatility in financial markets or for the securities of a particular company, group of companies, industry or other class of assets.

Adverse market conditions or particular market disruptions, such as those discussed above, may magnify the impact of each of the other risks described in this “MAIN RISKS” section and may increase volatility in one or more markets in which the fund invests leading to the potential for greater losses for the fund.

Interest rate risk. Rising interest rates could cause the value of the fund’s investments — and therefore its share price as well — to decline. A rising interest rate environment may cause investors to move out of fixed-income securities and related markets on a large scale, which could adversely affect the price and liquidity of such securities and could also result in increased redemptions from the fund. Increased redemptions from the fund may force the fund to sell investments at a time when it is not advantageous to do so, which could result in losses. A sharp rise in interest rates could cause the value of the fund’s investments to decline and impair the fund’s ability to maintain a stable $1.00 share price. Conversely, any decline in interest rates is likely to cause the fund’s yield to decline, and during periods of unusually low or negative interest rates, the fund’s yield may approach or fall below zero. A low or negative interest rate environment may prevent the fund from providing a positive yield or paying fund expenses out of current income and, at times, could impair the fund’s ability to maintain a stable $1.00 share price. Over time, the total return of a money market fund may not keep pace with inflation, which could result in a net loss of purchasing power for long-term investors. Interest rates can change in response to the supply and demand for credit, government and/or central bank monetary policy and action, inflation rates, and other factors. Changes in monetary policy made by central banks or governments

are likely to affect the level of interest rates. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility and potential illiquidity and may detract from fund performance to the extent the fund is exposed to such interest rates and/or volatility. Money market funds try to minimize interest rate risk by purchasing short-term securities. If there is an insufficient supply of US government securities to meet investor demand, it could result in lower yields on such securities and increase interest rate risk for the fund.

Credit risk. The fund's performance could be hurt and the fund's share price could fall below $1.00 if an issuer of a debt security suffers an adverse change in financial condition that results in the issuer not making timely payments of interest or principal, a security downgrade or an inability to meet a financial obligation.

For securities that rely on third-party guarantors to support their credit quality, the same risks may apply if the financial condition of the guarantor deteriorates or the guarantor ceases to insure securities. Because guarantors may insure many types of securities, including subprime mortgage bonds and other high-risk bonds, their financial condition could deteriorate as a result of events that have little or no connection to securities owned by the fund.

Some securities issued by US government agencies or instrumentalities are backed by the full faith and credit of the US government. Other securities that are supported only by the credit of the issuing agency or instrumentality are subject to greater credit risk than securities backed by the full faith and credit of the US government. This is because the US government might provide financial support, but has no obligation to do so, if there is a potential or actual loss of principal or failure to make interest payments.

US government default risk. Due to the rising US government debt burden and potential limitations caused by the statutory debt ceiling, it is possible that the US government may not be able to meet its financial obligations or that securities issued by the US government may experience credit downgrades. In the past, US sovereign credit has experienced downgrades and there can be no guarantee that it will not experience further downgrades in the future by rating agencies. Such a credit event may adversely impact the financial markets and the fund. From time to time, uncertainty regarding the status of negotiations in the US government to increase the statutory debt ceiling and/or failure to increase the statutory debt ceiling could increase the risk that the US government may default on payments on certain US government securities, cause the credit rating of the US government to be downgraded or increase volatility in financial markets, result in higher interest rates, reduce prices of US Treasury securities and/or increase the costs of certain kinds of debt.

Liquidity and transaction risk. The liquidity of portfolio securities can deteriorate rapidly due to credit events affecting issuers or guarantors or due to general market

DWS Money Market Prime Series

Summary Prospectus December 1, 2025

conditions and a lack of willing buyers. When there are no willing buyers and an instrument cannot be readily sold at a desired time or price, the fund may have to accept a lower price or may not be able to sell the instrument at all. The potential for liquidity risk may be magnified by a rising interest rate environment or other circumstances where investor redemptions from money market funds may be higher than normal, potentially causing increased supply in the market due to selling activity. If dealer capacity in debt instruments is insufficient for market conditions, it may further inhibit liquidity and increase volatility in the debt markets. Additionally, market participants other than the fund may attempt to sell debt holdings at the same time as the fund, which could cause downward pricing pressure and contribute to illiquidity. An inability to sell one or more portfolio securities can adversely affect the fund’s ability to maintain a $1.00 share price or prevent the fund from being able to take advantage of other investment opportunities.

Unusual market conditions, an unusually high volume of redemption requests or other similar conditions could cause the fund to be unable to pay redemption proceeds within a short period of time. If the fund is forced to sell securities at an unfavorable time and/or under unfavorable conditions, such sales may adversely affect the fund’s ability to maintain a $1.00 share price.

Security selection risk. Although short-term securities are relatively stable investments, it is possible that the securities in which the fund invests will not perform as expected. This could cause the fund's returns to lag behind those of similar money market funds and could result in a decline in share price.

Municipal securities risk. Municipal instruments may be susceptible to periods of economic stress, which could affect the market values and marketability of many or all municipal obligations of issuers in a state, US territory, or possession. The fund could also be impacted by events in the municipal securities market, including the supply and demand for municipal securities. Negative events, such as severe fiscal difficulties, bankruptcy of one or more issuers, an economic downturn, unfavorable legislation, court rulings or political developments, or reduced monetary support from the federal government could hurt fund performance. The municipal securities market can be susceptible to increases in volatility and decreases in liquidity. Liquidity can decline unpredictably in response to overall economic conditions or credit tightening. Increases in volatility and decreases in liquidity may be caused by a rise in interest rates (or the expectation of a rise in interest rates). Municipal securities may include revenue bonds, which are generally backed by revenue from a specific project or tax. The issuer of a revenue bond makes interest and principal payments from revenues generated from a particular source or facility, such as a tax on particular property or revenues generated from a municipal water or sewer utility or an airport. Revenue bonds generally are

not backed by the full faith and credit and general taxing power of the issuer. The value of municipal securities is strongly influenced by the value of tax-exempt income to investors. Changes in tax and other laws, including changes to individual or corporate tax rates, could alter the attractiveness and overall demand for municipal securities. Municipal securities may also have exposure to potential physical risks resulting from climate change, including extreme weather, flooding and fires. Climate risks, if they materialize, can adversely impact a municipal issuer’s financial plans in current or future years or may impair a facility or other source generating revenues backing a municipal issuer’s revenue bonds. As a result, the impact of climate risks may adversely impact the value of the fund’s shares.

Repurchase agreement risk. If the party that sells the securities to the fund defaults on its obligation to repurchase them at the agreed-upon time and price, the fund could lose money.

Counterparty risk. A financial institution or other counterparty with whom the fund does business, or that underwrites, distributes or guarantees any investments or contracts that the fund owns or is otherwise exposed to, may decline in financial health and become unable to honor its commitments. This could cause losses for the fund or could delay the return or delivery of collateral or other assets to the fund.

Concentration risk. Any fund that concentrates in a particular segment of the market will generally be more volatile than a fund that invests more broadly. Any market price movements, regulatory or technological changes, or economic conditions affecting banks or financial institutions will have a significant impact on the fund’s performance.

In particular, banks and other financial institutions are highly dependent on short-term interest rates and can be adversely affected by downturns in the US and foreign economies or changes in banking regulations.

Prepayment and extension risk. When interest rates fall, issuers of high interest debt obligations may pay off the debts earlier than expected (prepayment risk), and the fund may have to reinvest the proceeds at lower yields. When interest rates rise, issuers of lower interest debt obligations may pay off the debts later than expected (extension risk), thus keeping the fund’s assets tied up in lower interest debt obligations. Ultimately, any changes or unexpected behavior in interest rates could increase the volatility of the fund’s yield and could hurt fund performance. Prepayments could also create capital gains tax liability in some instances.

Foreign investment risk. Foreign investments include certain special risks, such as unfavorable political and legal developments, limited financial information, regulatory risk and economic and financial instability.

DWS Money Market Prime Series

Summary Prospectus December 1, 2025

Risks of holding cash. The fund will at times hold cash positions, which may hurt the fund’s performance. Cash positions may also subject the fund to additional risks and costs, including any fees imposed by the fund’s custodian for large cash balances.

Inflation risk. Inflation risk is the risk that the real value of certain assets or real income from investments (the value of such assets or income after accounting for inflation) will be less in the future as inflation decreases the value of money. Inflation, and investors’ expectation of future inflation, can impact the current value of the fund's portfolio, resulting in lower asset values and losses to shareholders. This risk may be elevated compared to historical market conditions and could be impacted by monetary policy measures and the current interest rate environment.

Operational and technology risk. Cyber-attacks, disruptions or failures that affect the fund’s service providers or counterparties, issuers of securities held by the fund, or other market participants may adversely affect the fund and its shareholders, including by causing losses for the fund or impairing fund operations. For example, the fund’s or its service providers’ assets or sensitive or confidential information may be misappropriated, data may be corrupted and operations may be disrupted (e.g., cyber-attacks, operational failures or broader disruptions may cause the release of private shareholder information or confidential fund information, interfere with the processing of shareholder transactions, impact the ability to calculate the fund’s net asset value and impede trading). Market events and disruptions also may trigger a volume of transactions that overloads current information technology and communication systems and processes, impacting the ability to conduct the fund’s operations.

While the fund and its service providers may establish business continuity and other plans and processes that seek to address the possibility of and fallout from cyber-attacks, disruptions or failures, there are inherent limitations in such plans and systems, including that they do not apply to third parties, such as fund counterparties, issuers of securities held by the fund or other market participants, as well as the possibility that certain risks have not been identified or that unknown threats may emerge in the future and there is no assurance that such plans and processes will be effective. Among other situations, disruptions (for example, pandemics or health crises) that cause prolonged periods of remote work or significant employee absences at the fund’s service providers could impact the ability to conduct the fund’s operations. In addition, the fund cannot directly control any cybersecurity plans and systems put in place by its service providers, fund counterparties, issuers of securities held by the fund or other market participants.

Past Performance

How a fund's returns vary from year to year can give an idea of its risk. Past performance may not indicate future results. All performance figures below assume that dividends were reinvested. The 7-day yield, which is often referred to as the “current yield,” is the income generated by the fund over a seven-day period. This amount is then annualized, which means that we assume the fund generates the same income every week for a year. For more recent performance figures and the current yield, go to dws.com (the Web site does not form a part of this prospectus) or call the telephone number included in this prospectus.

CALENDAR YEAR TOTAL RETURNS (%) (Class A)

Returns for other classes were different and are not shown here.

	Returns	Period ending
Best Quarter	1.19%	December 31, 2023
Worst Quarter	0.00%	March 31, 2015
Year-to-Date	2.71%	September 30, 2025

Average Annual Total Returns
(For periods ended 12/31/2024 expressed as a %) (Class A)

	Class Inception	1 Year	5 Years	10 Years
Class A	3/12/2007	4.55	2.09	1.38
Class C	3/12/2007	2.78	1.67	0.98
Class S	3/12/2007	4.84	2.26	1.54

Total returns would have been lower if operating expenses had not been reduced.

Management

Investment Advisor

DWS Investment Management Americas, Inc.

Purchase and Sale of Fund Shares

Minimum Initial Investment ($)

	Non-IRA	IRAs	UGMAs/ UTMAs	Automatic Investment Plans
A, C	1,000	500	1,000	500
S	2,500	1,000	1,000	1,000

DWS Money Market Prime Series

Summary Prospectus December 1, 2025

For participants in all group retirement plans, and in certain fee-based and wrap programs approved by the Advisor, there is no minimum initial investment and no minimum additional investment for Class A, C and S shares. For Section 529 college savings plans, there is no minimum initial investment and no minimum additional investment for Class S shares. The minimum initial investment for Class S shares may be waived for eligible intermediaries that have agreements with DDI to offer Class S shares in their brokerage platforms when such Class S shares are held in omnibus accounts on such brokerage platforms. The minimum additional investment in all other instances is $50.

To Place Orders

Mail	All Requests	DWS PO Box 219151 Kansas City, MO 64121-9151
Expedited Mail		DWS 801 Pennsylvania Ave Suite 219151 Kansas City, MO 64105-1307
Web Site		dws.com
Telephone		(800) 728-3337, M – F 8 a.m. – 7 p.m. ET
Hearing Impaired		For hearing impaired assistance, please call us using a relay service

Class S shares are available through certain intermediary relationships with financial services firms, or can be purchased by establishing an account directly with the fund’s transfer agent.

The fund is generally open on days when the New York Stock Exchange is open for regular trading. If you invest with the fund directly through the transfer agent, you can open a new fund account (Class S shares only) and make an initial investment on the Internet at dws.com, by using the mobile app or by mail. You can make additional investments or sell shares of the fund on any business day by visiting the fund’s Web site, by using the mobile app, by mail, or by telephone; however you may have to elect certain privileges on your initial account application. The ability to open new fund accounts and to transact online or using the mobile app varies depending on share class and account type. If you are working with a financial representative, contact your financial representative for assistance with buying or selling fund shares. A financial representative separately may impose its own policies and procedures for buying and selling fund shares.

The fund’s shares are available for purchase only by natural persons. The fund has implemented policies and procedures that are reasonably designed to limit beneficial ownership of the fund’s shares to natural persons.

Any new investors wishing to purchase shares of the fund may be required to demonstrate eligibility. If the fund subsequently determines that a beneficial owner of fund shares is not a natural person, then the fund, upon notice, will involuntarily redeem all of the shares of such ineligible investor and send the net proceeds to the investor.

Tax Information

The fund's distributions are generally taxable to you as ordinary income or capital gains, except when you are tax-exempt or when your investment is in an IRA, 401(k), or other tax-advantaged investment plan. Any withdrawals you make from such tax-advantaged investment plans, however, may be taxable to you.

Payments to Broker-Dealers and
Other Financial Intermediaries

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

DWS Money Market Prime Series

Summary Prospectus December 1, 2025 DCIT-SUM