Strategy. Under normal market conditions, the fund buys short-term debt securities and will invest at least 80% of its net assets in U.S. government securities, including U.S. Treasury securities and other securities issued or guaranteed by the U.S. government and its agencies and instrumentalities. In addition, the fund may invest a portion of its assets in investment-grade debt securities, including debt securities of U.S. companies, and non-U.S. government mortgage-backed, asset-backed and other fixed-income securities. Under normal market conditions, the portfolio managers maintain a weighted average maturity of three years or less. Securities issued or guaranteed by the U.S. Treasury and certain U.S. government agencies or instrumentalities, such as the Government National Mortgage Association (Ginnie Mae), are supported by the full faith … Show more… Under normal market conditions, the fund buys short-term debt securities and will invest at least 80% of its net assets in U.S. government securities, including U.S. Treasury securities and other securities issued or guaranteed by the U.S. government and its agencies and instrumentalities. In addition, the fund may invest a portion of its assets in investment-grade debt securities, including debt securities of U.S. companies, and non-U.S. government mortgage-backed, asset-backed and other fixed-income securities. Under normal market conditions, the portfolio managers maintain a weighted average maturity of three years or less. Securities issued or guaranteed by the U.S. Treasury and certain U.S. government agencies or instrumentalities, such as the Government National Mortgage Association (Ginnie Mae), are supported by the full faith and credit of the U.S. government. Securities issued or guaranteed by other U.S. government agencies or instrumentalities, such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), and the Federal Home Loan Bank are not guaranteed by the U.S. Treasury or supported by the full faith and credit of the U.S. government. However, these agencies or instrumentalities are authorized to borrow from the U.S. Treasury to meet their obligations. In general, securities issued by non-U.S. government entities such as corporations are backed only by the credit of the issuer. To generate additional income, the fund may purchase securities, including mortgage dollar rolls, in advance through when-issued and forward commitment transactions. The fund may commit up to 35% of its total assets to such transactions. The fund also may invest in derivative instruments such as options, futures contracts, options on futures contracts and swap agreements (including, but not limited to, credit default swap agreements), in mortgage- or asset-backed securities, or in pre-refunded municipal securities, provided that such investments are in keeping with the funds investment objective. When determining whether to sell a security, the portfolio managers consider, among other things, current and anticipated changes in interest rates, current valuation relative to alternatives in the market, general market conditions and any other factors deemed relevant by the portfolio managers. The fund may engage in active and frequent trading of portfolio securities to achieve its principal investment strategies. This may cause higher transaction costs and may affect performance. It may also result in the realization and distribution of capital gains. Show less