The Fund seeks to achieve its investment objective by investing, under normal circumstances, at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in component securities and instruments in the Fund's Underlying Index. Cash and cash equivalent investments associated with a derivative position will be treated as part of that position for the purposes of calculating the percentage of investments included in the Underlying Index. The Fund seeks to track the investment results of the Underlying Index before fees and expenses of the Fund. The Fund may also invest in other interest rate futures contracts, including but not limited to, U.S. Treasuries, Eurodollar and Federal Funds futures. The Fund's interest rate swap and futures positions are not intended to mitigate credit risk or other factors influencing the price of U.S. dollar-denominated, investment-grade bonds, which may have a greater impact than interest rates.