Investors in U.S.-based funds pulled $7 billion out of stock funds in the week that ended Wednesday, more than the two previous weeks' worth of net inflows, data from Thomson Reuters' Lipper service showed on Thursday.

That was the largest such outflow since early February, turning the four-week moving average to outflows for the first time since mid-February.

Investors pulled $8.6 billion out of stock exchange-traded funds while committing $1.6 billion to stock mutual funds. ETFs are thought to represent the institutional investor, while mutual funds are commonly purchased by retail investors.

Taxable bond funds attracted $4.7 billion in inflows, marking their ninth straight week of inflows.

Low-risk money market funds posted $17.8 billion in net new cash, the largest such inflows since December.