The iShares Core Total USD Bond Market ETF (IUSB) has doubled the year-to-date inflows of the Bloomberg Aggregate Bond Index ETF (AGG), ranking third overall in fixed-income flows. Analysts project IUSB could surpass AGG in total assets by the end of the decade as investors increasingly adopt the fund as a core portfolio holding due to its exposure to high-yield and international debt. The broader scope of the Universal Bond Index presents a more competitive benchmark for active bond managers compared to the traditional aggregate index. This shift reflects growing demand for diversified fixed-income strategies that extend beyond standard U.S. investment-grade bonds.