Treasury Secretary Timothy Geithner said Thursday "more work remains" to ensure the government has tough regulations over money market funds.
In testimony before a panel looking into the causes of the financial crisis, Geithner said the government needs to work to ensure that funds are less susceptible to runs. Investors pulled massive amounts of money from the funds during the financial crisis as the funds' investments in debt from companies, including Lehman Brothers, rapidly deteriorated.
The funds are a major buyer of short-term debt, which is used as a source of financing by a wide range of financial and other companies.
Geithner said the President's Working Group on Financial Markets is preparing a report on the funds and ways to reduce their risks.
"More work remains to be done in this area," Geithner said.