Total money market mutual fund assets decreased by $4.49 billion to $3.116 trillion in the week ending Dec. 19, according to the Investment Company Institute.
Retail money market fund assets rose by $5.75 billion to $1.148 trillion.
Among the 857 retail-class shares, assets of the 555 taxable shares increased by $3 billion to $870.79 billion, and assets of the 302 tax-exempt shares increased by $2.75 billion to $276.85 billion.
Institutional-class money market fund assets fell by $10.24 billion to $1.969 trillion in the week, the industry trade group said. Taxable money market fund assets fell by $5.58 billion to $1.784 trillion and assets of tax-exempt funds fell by $4.67 billion to $184.73 billion.
The average seven-day yield on money market mutual funds fell for the week ending Dec. 18, from 4.16% to 4.08%, according to the Money Fund Report, published by iMoneyNet Inc. The seven-day compounded yield fell from 4.24% to 4.16%.