iShares Short-Term National Muni Bond ETF(AMEX:SUB)

SUB provides broad exposure to a range of USD-denominated municipal bonds, with an emphasis on the shorter end of the yield curve. Debt securities must have a remaining final maturity of at least one month and less than five years, while seeking to maintain a weighted average maturity of less than three years. SUB primarily invests in investment-grade securities and will weight its constituents by market value. The fund uses a sampling method to track the index, meaning the fund may not hold all the securities of the underlying index but will hold securities that collectively have the same investment profile. Rebalancing is done after the close on the last business day of each month. Prior to September 15, 2021, the fund tracks the S&P Short Term National AMT-Free Municipal Bond Index.