HYD provides exposure to the high-yield municipal ETF space with an issuer-capped index, which produces a different geographic exposure and credit risk profile than the broad market. It holds tax-exempt high-yield bonds of varying maturities, with a tilt towards longer-term securities. The underlying index consists of USD-denominated municipal bonds, allocating 70% to high-yield, 25% to BBB-rated, and 5% to A-rated securities. The index weights its components by market value and rebalances monthly. The fund uses a sampling method in tracking the index, which means it will invest in a sample of securities that collectively have an investment profile similar to that of the underlying index. Prior to March 1, 2022, the fund tracked the Bloomberg Municipal Custom High Yield Composite Index. Then until November 30, 2022, the fund used a transition index to gradually broaden its exposure before tracking its current index.