The Fund seeks to track the investment results of the ICE AMT-Free US National Municipal Index (the Underlying Index), which measures the performance of U.S. dollar denominated investment grade tax-exempt debt publicly issued in the U.S. domestic market by U.S. states and their political subdivisions. As of February 29, 2024, there were 23,383 issues in the Underlying Index. As of February 29, 2024, a significant portion of the Underlying Index is represented by municipal bonds. The components of the Underlying Index are likely to change over time. The Underlying Index includes municipal bonds, the interest of which is exempt from Federal income taxes and not subject to alternative minimum tax. Each bond in the Underlying Index must have a rating of at least BBB minus by Standard & Poors Global Ratings, a subsidiary of S&P Global, Baa3 by Moodys Investors Service, Inc., or BBB- by Fitch Ratings, Inc. A bond must be rated by at least one of these three rating agencies in order to qualify for the Underlying Index, and the lowest rating will be used in determining if the bond is investment grade. Each bond in the Underlying Index must be a constituent of an offering where the original offering amount was at least dollar 100 million and have a minimum par amount (i.e., currently outstanding face value) of dollar 15 million. In addition, each bond must have a minimum remaining term to final maturity greater than or equal to one calendar month to be included in the Underlying Index. The Underlying Index is a market-value weighted index and is subject to a capping methodology that aims at reducing index concentration. The Underlying Index is rebalanced on the last calendar day of the month.