The investment seeks to track the investment results of the Bloomberg Barclays 2023 Maturity Corporate Index which composed of U.S. dollar-denominated, investment-grade corporate bonds maturing after March 31, 2022 and before April 1, 2023. The fund generally will invest at least 90% of its assets in the component securities (including indirect investments through an underlying fund) of the underlying index, and may invest up to 10% of its assets in certain futures, options and swap contracts, cash and cash equivalents, as well as in securities not included in the underlying index, but which BFA believes will help the fund track the underlying index.