The fund generally will invest at least 80% of its total assets in securities that comprise the underlying index. The underlying index seeks to measure the performance of a portfolio of U.S. dollar-denominated investment grade corporate bonds with maturities or, in some cases, "effective maturities" in the year 2030. It does not purchase all of the securities in the index; instead, the fund utilizes a "sampling" methodology to seek to achieve its investment objective.