The investment seeks to maximize long-term total return. The fund invests primarily in a diversified portfolio of debt securities. These include debt obligations issued or guaranteed by the U.S. government and foreign governments and their agencies and instrumentalities, debt securities issued by U.S. and foreign companies, collateralized mortgage obligations, and U.S. and foreign mortgage-backed and asset-backed debt securities. The fund may invest in debt instruments of any maturity or with no maturity and it may invest in both investment-grade securities and non-investment grade securities (also known as "high-yield bonds" or "junk bonds").