0000055189 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:ClassAbcsMember 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:ClassAbcsMember dim4:C000035161Member 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:ClassAbcsMember dim4:C000035162Member 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:ClassAbcsMember dim4:C000035163Member 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:ClassAbcsMember dim4:C000035164Member 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:DwsMoneyMarketFundMember 2011-12-02 2012-12-01 0000055189 dim4:S000006073Member dim4:DwsMoneyMarketFundMember dim4:C000016691Member 2011-12-02 2012-12-01 pure iso4217:USD 485BPOS DWS MONEY FUNDS 0000055189 2012-11-28 false 2012-12-01 2012-12-01 2012-07-31 DWS Money Market Prime Series Investment Objective The fund seeks maximum current income to the extent consistent with stability of principal. Fees and Expenses of the Fund These are the fees and expenses you may pay when you buy and hold shares. SHAREHOLDER FEES (paid directly from your investment) ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a % of the value of your investment) 0 0 0 0 0 0.04 0.01 0 20 20 20 20 0.002 0.002 0.002 0.002 0.0025 0.01 0.01 0 0.0038 0.0036 0.003 0.0032 0.0083 0.0156 0.015 0.0052 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 remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be: You would pay the following expenses if you did not redeem your shares: Class B converts to Class A after six years; the Example for Class B reflects Class A fees after the conversion. 85 265 460 1025 159 493 850 1480 153 474 818 1791 53 167 291 653 85 559 253 53 265 793 474 167 460 1050 818 291 1025 1480 1791 653 Principal Investment Strategy The fund is managed in accordance with Rule 2a-7 under the Investment Company Act of 1940, as amended, which governs 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, 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 mutual funds. 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. Securities Lending. The fund may lend securities (up to one-third of total assets) to approved institutions. 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. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. Although the fund seeks to preserve the value of your investment at $1.00 per share, this share price isn't guaranteed, and if it falls below $1.00 you would lose money. The Advisor is not obligated to take any action to maintain the $1.00 share price. The share price could fall below $1.00 as a result of the actions of one or more large investors in the fund. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00, as could periods of high redemption pressures and/or illiquid markets. Interest rate risk. Rising interest rates could cause the value of the fund's investments — and therefore its share price as well — to decline. Conversely, any decline in interest rates is likely to cause the fund's yield to decline, and during periods of unusually low interest rates, the fund's yield may approach zero. A low 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. Credit risk. The fund's performance could be hurt if an issuer of a money market instrument suffers an adverse change in financial condition that results in a payment default, security downgrade or inability to meet a financial obligation. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00. Some securities issued by US government agencies or instrumentalities are backed by the full faith and credit of the US government. Others are supported only by the credit of that agency or instrumentality. For this latter group, if there is a potential or actual loss of principal and interest on these securities, the US government might provide financial support, but has no obligation to do so. Because of the rising US government debt burden, 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. Such a credit event may also adversely impact the financial markets. Liquidity risk. The liquidity of portfolio securities can deteriorate rapidly due to credit events affecting issuers or guarantors or due to general market 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. 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 mutual funds and could result in a decline in share price. 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. 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 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. Regulatory risk. In 2010, the SEC adopted amendments to then-existing money market fund regulations, imposing new liquidity, credit quality, and maturity requirements on all money market funds. In November 2012, the Financial Stability Oversight Committee (FSOC), a board of U.S. regulators established by the Dodd-Frank Act, proposed recommendations for money market fund reform. If the SEC were to adopt one or more of the FSOC proposed recommendations in the future, or if FSOC were to take other steps to establish similar regulations of money market funds in the future, such regulatory action may affect the fund's operations and/or return potential. Securities lending risk. Any decline in the value of a portfolio security that occurs while the security is out on loan is borne by the fund and will adversely affect performance. Also, there may be delays in recovery of securities loaned or even a loss of rights in the collateral should the borrower of the securities fail financially while holding the security. 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. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. Money market fund risk. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. Although the fund seeks to preserve the value of your investment at $1.00 per share, this share price isn't guaranteed, and if it falls below $1.00 you would lose money. The Advisor is not obligated to take any action to maintain the $1.00 share price. The share price could fall below $1.00 as a result of the actions of one or more large investors in the fund. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00, as could periods of high redemption pressures and/or illiquid markets. 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. 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 www.dws-investments.com (the Web site does not form a part of this prospectus) or call the phone number included in this prospectus. For all share classes, historical performance prior to class inception is based on the performance of the fund's original share class, DWS Money Market Fund shares, adjusted to reflect the higher expenses and applicable sales charges of the relevant share class. DWS Money Market Fund shares are offered in a separate prospectus. How a fund's returns vary from year to year can give an idea of its risk. www.dws-investments.com Past performance may not indicate future results. Returns for other classes were different and are not shown here. CALENDAR YEAR TOTAL RETURNS (%) (Class A) Best Quarter: 1.16%, Q3 2007 Worst Quarter: 0.00%, Q1 2010 Year-to-Date as of 9/30/12: 0.01% Average Annual Total Returns (for periods ended 12/31/2011 expressed as a %) 0.0098 0.0031 0.0045 0.0236 0.0419 0.0456 0.0227 0.0018 0.0002 0.0001 Year-to-Date 2012-09-30 0.0001 Best Quarter: 2007-09-30 0.0116 Worst Quarter: 2010-03-31 0 2007-03-12 2007-03-12 2007-03-12 2007-03-12 0.0001 0.0001 0.0001 0.0001 0.0139 0.0104 0.0108 0.0155 0.0152 0.0084 0.0106 0.0175 <div style="display:none">~ http://www.dws-investments.com/role/ScheduleShareholderFeesDWSMoneyMarketPrimeSeries column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAnnualFundOperatingExpensesDWSMoneyMarketPrimeSeries column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleExpenseExampleDWSMoneyMarketPrimeSeries column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleExpenseExampleNoRedemptionDWSMoneyMarketPrimeSeries column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAnnualTotalReturnsDWSMoneyMarketPrimeSeriesBarChart column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAverageAnnualTotalReturnsTransposedDWSMoneyMarketPrimeSeries column period compact * ~</div> DWS Money Market Prime Series Investment Objective Fees and Expenses of the Fund SHAREHOLDER FEES (paid directly from your investment) ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a % of the value of your investment) EXAMPLE Principal Investment Strategy Main Risks Past Performance CALENDAR YEAR TOTAL RETURNS (%) (DWS Money Market Fund) Average Annual Total Returns (for periods ended 12/31/2011 expressed as a %) www.dws-investments.com The fund seeks maximum current income to the extent consistent with stability of principal. These are the fees and expenses you may pay when you buy and hold shares. 0.00 0.002 0 0.0025 0.0045 20 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 remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be: 46 144 252 567 The fund is managed in accordance with Rule 2a-7 under the Investment Company Act of 1940, as amended, which governs 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, 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 mutual funds. 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. Securities Lending. The fund may lend securities (up to one-third of total assets) to approved institutions. 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. 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. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. Although the fund seeks to preserve the value of your investment at $1.00 per share, this share price isn't guaranteed, and if it falls below $1.00 you would lose money. The Advisor is not obligated to take any action to maintain the $1.00 share price. The share price could fall below $1.00 as a result of the actions of one or more large investors in the fund. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00, as could periods of high redemption pressures and/or illiquid markets. Interest rate risk. Rising interest rates could cause the value of the fund's investments — and therefore its share price as well — to decline. Conversely, any decline in interest rates is likely to cause the fund's yield to decline, and during periods of unusually low interest rates, the fund's yield may approach zero. A low 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. Credit risk. The fund's performance could be hurt if an issuer of a money market instrument suffers an adverse change in financial condition that results in a payment default, security downgrade or inability to meet a financial obligation. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00. Some securities issued by US government agencies or instrumentalities are backed by the full faith and credit of the US government. Others are supported only by the credit of that agency or instrumentality. For this latter group, if there is a potential or actual loss of principal and interest on these securities, the US government might provide financial support, but has no obligation to do so. Because of the rising US government debt burden, 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. Such a credit event may also adversely impact the financial markets. Liquidity risk. The liquidity of portfolio securities can deteriorate rapidly due to credit events affecting issuers or guarantors or due to general market 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. 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 mutual funds and could result in a decline in share price. 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. 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 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. Regulatory risk. In 2010, the SEC adopted amendments to then-existing money market fund regulations, imposing new liquidity, credit quality, and maturity requirements on all money market funds. In November 2012, the Financial Stability Oversight Committee (FSOC), a board of U.S. regulators established by the Dodd-Frank Act, proposed recommendations for money market fund reform. If the SEC were to adopt one or more of the FSOC proposed recommendations in the future, or if FSOC were to take other steps to establish similar regulations of money market funds in the future, such regulatory action may affect the fund's operations and/or return potential. Securities lending risk. Any decline in the value of a portfolio security that occurs while the security is out on loan is borne by the fund and will adversely affect performance. Also, there may be delays in recovery of securities loaned or even a loss of rights in the collateral should the borrower of the securities fail financially while holding the security. 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. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. Although the fund seeks to preserve the value of your investment at $1.00 per share, this share price isn't guaranteed, and if it falls below $1.00 you would lose money. The Advisor is not obligated to take any action to maintain the $1.00 share price. The share price could fall below $1.00 as a result of the actions of one or more large investors in the fund. The credit quality of the fund's holdings can change rapidly in certain markets, and the default of a single holding could cause the fund's share price to fall below $1.00, as could periods of high redemption pressures and/or illiquid markets. An investment in the fund is not insured or guaranteed by the FDIC or any other government agency. 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 www.dws-investments.com (the Web site does not form a part of this prospectus) or call the phone number included in this prospectus. How a fund's returns vary from year to year can give an idea of its risk. Past performance may not indicate future results. Returns for other classes were different and are not shown here. Best Quarter: 1.28%, Q3 2007 Worst Quarter: 0.00%, Q1 2010 Year-to-Date as of 9/30/2012: 0.01% 0.0149 0.0081 0.0096 0.0287 0.0471 0.0506 0.0269 0.0035 0.0002 0.0001 Year-to-Date 2012-09-30 0.0001 Best Quarter: 2007-09-30 0.0128 Worst Quarter: 2010-03-31 0 1974-11-25 0.0001 0.016 0.0188 Total returns would have been lower if operating expenses hadn't been reduced. Total returns would have been lower if operating expenses hadn't been reduced. <div style="display:none">~ http://www.dws-investments.com/role/ScheduleShareholderFeesDWSMoneyMarketPrimeSeriesDWSMoneyMarketFund column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAnnualFundOperatingExpensesDWSMoneyMarketPrimeSeriesDWSMoneyMarketFund column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleExpenseExampleTransposedDWSMoneyMarketPrimeSeriesDWSMoneyMarketFund column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleExpenseExampleNoRedemptionDWSMoneyMarketPrimeSeriesDWSMoneyMarketFund column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAnnualTotalReturnsDWSMoneyMarketPrimeSeriesDWSMoneyMarketFundBarChart column period compact * ~</div> <div style="display:none">~ http://www.dws-investments.com/role/ScheduleAverageAnnualTotalReturnsTransposedDWSMoneyMarketPrimeSeriesDWSMoneyMarketFund column period compact * ~</div>