iShares Government Money Market ETF (GMMF) is an exchange-traded fund in the Money Market Taxable category. It has $177.54M in assets, an expense ratio of 0.20% and a 3.86% dividend yield. The fund invests at least 99.5% of its total assets in cash, U.S. Treasury bills, notes and other obligations issued or guaranteed as to principal and interest by the U.S. government, its agencies or instrumentalities. It invests, under normal circumstances, at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in U.S. Treasury bills, notes and other obligations issued or guaranteed as to principal and interest by the U.S. government, its agencies or instrum…