Strategy. Under normal market conditions, the Fund invests at least 80% of its net assets in mortgage securities. The Fund invests significantly in mortgage securities that are issued or guaranteed by the U.S. government, its agencies or instrumentalities, which include mortgage pass-through securities representing interests in "pools" of mortgage loans issued or guaranteed by the Government National Mortgage Association (Ginnie Mae), Fannie Mae, and Freddie Mac. These securities may be fixed-rate or adjustable-rate mortgage securities (ARMS). Securities issued by different government agencies or instrumentalities have different levels of credit support. The Fund may purchase or sell mortgage-backed securities on a delayed delivery or forward commitment basis through the "to-be-announced" (TBA) market. With TBA transactions, the particular securities to be delivered must … Show more… Under normal market conditions, the Fund invests at least 80% of its net assets in mortgage securities. The Fund invests significantly in mortgage securities that are issued or guaranteed by the U.S. government, its agencies or instrumentalities, which include mortgage pass-through securities representing interests in "pools" of mortgage loans issued or guaranteed by the Government National Mortgage Association (Ginnie Mae), Fannie Mae, and Freddie Mac. These securities may be fixed-rate or adjustable-rate mortgage securities (ARMS). Securities issued by different government agencies or instrumentalities have different levels of credit support. The Fund may purchase or sell mortgage-backed securities on a delayed delivery or forward commitment basis through the "to-be-announced" (TBA) market. With TBA transactions, the particular securities to be delivered must meet specified terms and conditions. The Fund also invests in other types of mortgage securities including, but not limited to, certain ARMS, commercial mortgage-backed securities (CMBS), non-agency residential mortgage-backed securities (RMBS), credit risk transfer securities, home equity loan asset-backed securities (HELs), manufactured housing asset-backed securities (MHs), and collateralized mortgage obligations (CMOs), as well as in other mortgage-related asset-backed securities. Mortgage securities may include interests in reperforming loans (mortgage loans that are current but had been delinquent in the past). The Fund also may invest in U.S. Treasury securities. The Fund may invest a small portion of its assets directly in whole mortgage loans. The Fund may invest up to 15% of its net assets in foreign securities, which may include non-U.S. dollar denominated foreign mortgage securities. In addition, the Fund may invest up to 20% of its net assets in high-yield, lower-quality securities rated, at the time of purchase, below BBB by S&P , or Baa by Moodys, respectively, or, if unrated, deemed to be of comparable quality by the investment manager. The Fund may also invest up to 33% of its total assets in mortgage dollar rolls. For purposes of pursuing its investment goal, the Fund may enter into interest rate and credit related derivative instruments, including interest rate and credit default swaps and bond/interest rate futures contracts. The Fund may also enter into currency-related derivative transactions, including currency forwards and currency swaps. The Fund may use these derivative instruments for hedging purposes or for other investment purposes, including to generate income, to increase liquidity and/or to gain exposure to certain instruments or markets in a more efficient or less expensive way. The use of credit default swaps may allow the Fund to obtain net long or short exposure to select credit risks. Show less