Strategy. Under normal market conditions, the fund invests at least 80% of its net assets in securities issued by the Government National Mortgage Association (GNMA). GNMA certificates represent interests in pools of mortgage loans and in the cash flows from these loans. Unlike many other mortgage-backed securities, the timely payment of principal and interest on these certificates is guaranteed by GNMA. GNMAs payment guarantee is stronger than most other government agencies because it is backed by the full faith and credit pledge of the U.S. government. In addition, the fund may buy other U.S. government debt securities, including U.S. Treasury securities and other securities issued or guaranteed by the U.S. government and its agencies and instrumentalities. Securities issued or guaranteed by … Show more… Under normal market conditions, the fund invests at least 80% of its net assets in securities issued by the Government National Mortgage Association (GNMA). GNMA certificates represent interests in pools of mortgage loans and in the cash flows from these loans. Unlike many other mortgage-backed securities, the timely payment of principal and interest on these certificates is guaranteed by GNMA. GNMAs payment guarantee is stronger than most other government agencies because it is backed by the full faith and credit pledge of the U.S. government. In addition, the fund may buy other U.S. government debt securities, including U.S. Treasury securities and other securities issued or guaranteed by the U.S. government and its agencies and instrumentalities. 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. 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, or in mortgage- or asset-backed 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