The investment seeks to provide a total return that matches or incrementally exceeds the performance of the U.S. investment-grade bond market. The fund normally invests at least 80% of its net assets in U.S. bonds and in securities that are represented in the fund’s benchmark index. Consistent with the benchmark index, the fund’s holdings will normally include U.S. government and agency obligations, mortgage- and asset-backed securities, corporate bonds, and U.S. dollar-denominated securities of foreign issuers. The index is market capitalization weighted and the securities represented in the index are updated on the last business day of each month.