On July 23, the SEC adopted amendments to the rules that govern money market mutual funds. The new rules require a floating net asset value (NAV) for institutional prime money market funds to fluctuate, which allows the daily share prices of these funds to fluctuate along with changes in the market-based value of fund assets. This provides non-government money market fund boards with new tools— liquidity fees and redemption gates—to address the problem of investor runs. With a floating NAV, institutional prime money market funds are required to value their portfolio securities using market-based factors and sell and redeem shares based on a floating NAV. Release. Final Rule.