Assets of money market mutual funds rose a slim 0.1%, to $657.77 billion, in the week that ended May 10, the Investment Company Institute reported.
The gain was concentrated in funds for institutional investors, which attracted $1.22 billion, to close the week at $193.98 billion.
That includes $169.69 billion in taxable funds, up $799.3 million, and $24.3 billion in tax-exempt funds, up $421.22 million.
On the retail side, money market fund assets slipped $533.9 million, to $463.79 billion. Taxable funds shed $38.8 million, ending the week at $370.79 billion, while tax-exempt funds dropped $572.7 million, to $92.99 billion.