The investment seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Markit iBoxx® USD Liquid Investment Grade Index (the "underlying index"). The fund generally invests at least 90% of its assets in securities of the underlying index and at least 95% of its assets in investment grade corporate bonds. The underlying index is a rules-based index consisting of liquid, U.S. dollar-denominated, investment grade corporate bonds for sale in the United States, as determined by the index provider.