BAB accesses specific nichetaxable municipal bondsutilizing a plain-vanilla market-value selection and weighting process. BAB holds investment-grade taxable munis across all states and locales. Taxable munis generally carry higher yields than their tax-exempt counterparts, reflecting a premium for both the added tax burden and the lower liquidity typical to these securities. As such, BAB might be a good alternative for foreign investors who do not enjoy favorable tax treatment or for US investors seeking higher yield in a tax-advantaged account. BAB changed its underlying index from the BofA Merrill Lynch Build America Bond Index to the ICE BofAML US Taxable Municipal Securities Plus Index on 6/1/2017. The change materially broadened BAB's exposure to all taxable municipal securities.