The fund normally invests primarily in investment grade debt securities, which may include: investment grade corporate securities, U.S. government obligations, mortgage-backed securities guaranteed by U.S. government agencies and instrumentalities, and private residential mortgage-backed securities. Under normal circumstances, it invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in fixed income securities. The fund's portfolio weighted average duration will typically range from 3 to 10 years.