Investors pulled nearly $7.5 billion out of mutual funds and exchange-traded funds that hold U.S. stocks last week, extending a retreat from the domestic stock market over six of the last seven weeks, according to data released Wednesday by the Investment Company Institute.

The pullback from U.S. equities came during a week in which the S&P 500 notched record highs due to signs of progress in the U.S.-China trade talks.

But concerns about the strength of the global economy and the high valuation of the U.S. equity market have continued to weigh on long-term investor sentiment.

At the same time, investors sent $3.5 billion into world equity funds last week, the largest move into the category since early February and a sign that they may be looking for better values at a time when the S&P 500 is up more than any other developed market index since the beginning of the year.

Investors continued to seek out the perceived safety of bonds, sending nearly $12.7 billion to taxable and municipal debt funds last week.

That was the largest weekly inflow since early September and pushed the year-to-date gains for the category to slightly more than $378 billion. U.S. equity funds, by comparison, have shed $126.2 billion over the same time.