The Fund seeks to track the investment results of the Markit iBoxx USD Liquid Investment Grade Index (the Underlying Index), which is a rules-based index consisting of U.S. dollar-denominated, investment-grade (as determined by Markit Indices Limited (the Index Provider or Markit)) corporate bonds for sale in the U.S. The Underlying Index is designed to provide a broad representation of the U.S. dollar-denominated liquid investment-grade corporate bond market. The Underlying Index is a modified market-value weighted index with a cap on each issuer of 3 percent. There is no limit to the number of issues in the Underlying Index. As of February 29, 2024, the Underlying Index included approximately 2,748 constituents. As of February 29, 2024, a significant portion of the Underlying Index is represented by securities of companies in the financials industry or sector. The components of the Underlying Index are likely to change over time.