January 27, 2010 Kiplinger NewsAfter money-market fund prices "broke the buck" and dipped below $1 in September 2008, the Securities and Exchange Commission has been studying how best to change the rules regulating the funds. Changes to money-market mutual fund rules may be forthcoming, according to the Securities and Exchange Commission. SEC chairman Mary Schapiro said in an open meeting on Wednesday that the net asset value, or NAV, of money-market funds could be floated. That change would mark a shift from the longstanding policy of maintaining the funds' NAVs at $1. The funds are a source of liquidity for both corporations and individuals. By investing in high-quality debt instruments set to mature in no more than 13 months, they attempt to provide stable returns and to never lose money, i.e., to keep their NAV higher than $1. But the funds' stability -- a major selling point for issuers -- was called into question after the collapse of Lehman Brothers in September 2008. The oldest money market fund, Reserve Primary Fund, broke the buck after it had to write off Lehman debt, and a run on the funds ensued. Since that incident, the SEC has been considering rule changes. Its rules would "improve liquidity, increase credit quality and shorten maturity limits," the commission said.