DWS EQUITY 500 INDEX FUND CLASS R6 (BTIRX) Exchange: NMFQS

Main investments. Under normal circumstances, the Portfolio intends to invest at least 80% of assets, determined at the time of purchase, in stocks of companies included in the S&P 500® Index and in derivative instruments, such as futures contracts and options, that provide exposure to the stocks of companies in the index. The Portfolio's securities are weighted to attempt to make the Portfolio's total investment characteristics similar to those of the index as a whole. The Portfolio may also hold short-term debt securities and money market instruments. The S&P 500® Index is a well-known stock market index that includes common stocks of 500 companies from several industrial sectors representing a significant portion of the market value of all stocks publicly traded in the US. Stocks in the S&P 500® Index are weighted according to their total market value. The fund is not sponsored, endorsed, sold or promoted by the Standard & Poor's (S&P) Division of The McGraw-Hill Companies, Inc. While the market capitalization range of the S&P 500® Index changes throughout the year, as of February 28, 2018, the market capitalization range of the S&P 500® Index was between $2.6 billion and $905.1 billion. The S&P 500® Index is rebalanced quarterly on the third Friday of March, June, September and December. Management process. Portfolio management uses quantitative analysis techniques to structure the Portfolio to seek to obtain a high correlation to the index while seeking to keep the Portfolio as fully invested as possible in all market environments. Portfolio management seeks a long-term correlation between Portfolio performance, before expenses, and the index of 98% or better (perfect correlation being 100%). Portfolio management uses an optimization strategy, buying the largest stocks in the index in approximately the same proportion they represent in the index, then investing in a statistically selected sample of the smaller securities found in the index. Portfolio management's optimization process is intended to produce a portfolio whose industry weightings, market capitalizations and fundamental characteristics (price-to-book ratios, price-to-earnings ratios, debt-to-asset ratios and dividend yields) closely replicate those of the index. This approach attempts to maximize the Portfolio's liquidity and returns while minimizing its costs.Derivatives. Portfolio management generally may use futures contracts, which are a type of derivative (a contract whose value is based on, for example, indices, currencies or securities), to keep cash on hand to meet shareholder redemptions or for other needs while maintaining exposure to the stock market.The fund may also use other types of derivatives (i) for hedging purposes; (ii) for risk management; (iii) for non-hedging purposes to seek to enhance potential gains; or (iv) as a substitute for direct investment in a particular asset class or to keep cash on hand to meet shareholder redemptions.Securities Lending. The Portfolio may lend securities (up to one-third of total assets) to approved institutions, such as registered broker-dealers, banks and pooled investment vehicles.