The Securities and Exchange Commission voted unanimously to move ahead with changes governing the money market fund industry.
The proposal voted on Wednesday could force some kinds of money market funds to do away with the fixed $1 a share value that has made them so popular with many investors. Only so-called prime money funds, that invest in corporate debt, and that are available to big institutional investors would likely have to make the change, leaving funds used by ordinary investors largely untouched.
Money funds are supposed to be one of the safest investments. But during the financial crisis, there was a run on the industry after one of the largest funds fell below $1 a share. The market recovered only after winning unusual government guarantees.
The new rules still face a final vote, which will come after an open comment period of at least three months. In the proposal voted on Wednesday, the S.E.C. staff suggested that prime funds move to a so-called floating share value, or institute penalties for investors who pull their investments out of money funds in times of crisis. The five S.E.C. commissioners could also choose to combine the rules or choose from other options laid out in the report.
The proposal is already attracting criticism for not going far enough.
All the rules are aimed to avoid the situation money funds faced in 2008 when the declining value of one of the largest money market funds caused a run on the entire industry.
An earlier attempt to move ahead with similar proposals was foiled last summer after three commissioners stated their opposition. After a council of regulators pushed the S.E.C. to move ahead with changes, the commissioners unified behind the current set of proposed rules. The rules are more limited than the broad changes that a number of other regulators have called for in the past.
