The fund invests in fixed income securities of various maturities, yields, and qualities. Under normal circumstances, the fund will invest at least 80% of its assets in bonds, which include fixed income securities such as corporate bonds; U.S. Treasury obligations and other U.S. government and agency securities; and asset-backed, mortgage-backed and mortgage-related securities. The fund's dollar-weighted average maturity will normally range between 4 and 12 years, and may either be longer or shorter under certain market conditions.