Investors turned their backs on risk during the most volatile stretch of the second quarter, and they aren t showing signs of coming back soon.

More money was pulled out of mutual funds than put into them during the month of May, according to the Investment Company Institute, an industry research firm. Investors took $11.98 billion out of long-term funds, including stocks, bonds and hybrid funds (a combination of stocks and bonds), in May, marking the first time since March 2009 that more money was withdrawn than committed to the funds.

Stock funds saw an exodus of $24.67 billion in May, after an infusion of $13.24 billion in April, as investors fled to safer asset classes.

The flight to safety in May came amid worries about the European economy and as the so-called flash crash on May 11, when the market plunged in minutes, spooked investors, says Sonya Morris, director of the Morningstar mutual fund analyst team. The movement of investor dollars represents an expression of general fear and the desire to take risk off the table, she says. Another indication of that was the flow of money out of high-yield bond funds, which tend to be riskier, she says.

Money tends to chase relative performance, but in May, investors were also acting on sentiment, says Bill Stone, chief market strategist at PNC Wealth Management. The last weekly sentiment survey in May from the American Association of Individual Investors showed that bullish sentiment, or expectations that stocks would rise for the next six months, fell 11.5 percentage points to 29.8%. (The historical average is 39%.)

Investors may have gotten too aggressive trying to make up for the last two years and overreacted in the opposite direction, says Ameriprise advisor Rich Atkison. He cautions that withdrawing during a moment of panic, particularly in a market dip, has negative consequences, but adds that investors who need the money in the next three years should never be in equities to begin with.

Economic uncertainty overseas has also caused investors to reassess risk. However, the ICI data suggest stock funds that invest domestically lost their appeal, as well. Investors took $18.92 billion out of funds that invest primarily in the U.S., compared to $5.75 billion out of funds that invest primarily overseas. (Although the dollar amounts suggest foreign funds made out much better, those losses were comparable on a percentage basis, according to ICI.)

Investors who shunned equities looked again to traditionally safer investments but put fewer dollars to work, allocating $14.59 billion to bond funds in May, compared with $28.13 billion in April. Taxable bond funds saw $11.99 billion in new investor dollars in May, and municipal bond funds had an inflow of $2.60 billion.

The net withdrawal from funds overall may not represent a trend -- yet. Morningstar s Morris says market volatility softened in June, so we might not see the big spikes in outflows that we saw in May, but it s too soon to tell.

Through June 16, weekly data had suggested more money was flowing into funds this month than out of them, albeit just slightly with $2 to $3 billion being added per week. However, the last week of June was not encouraging and likely offset those first few weeks, says PNC s Stone.