Investors in the 401(k)-style retirement savings plan for federal employees reacted to recent stock market volatility and downturns by becoming more conservative in their investments overall, although the percentages of participants who took action and the money involved were relatively low.

Data released at the Thrift Savings Plan’s monthly board meeting Friday showed that during August, a month of several nerve-shattering losses in stock markets, investors made roughly double the average monthly number of transfers among the TSP investment funds. On a net basis they moved more than $2 billion into the TSP’s two most conservative investment funds, a government securities fund and a mixed government/corporate bond fund.

“We had significant movement to a flight to safety,” said TSP executive director Gregory T. Long.

“August was not a pretty month for the stock market and the TSP,”chief investment officer Tracey A. Ray said. “It was a very bad month for equities.”

The TSP has 4.5 million participants, including active and retired federal employees and military personnel, as well as former employees and uniformed personnel who separated before retirement but left their accounts in place. As of the end of August, their investments were worth $281 billion, down from $288 billion at the end of July despite an inflow of about $2 billion in new investments.

During August the number of transfers among funds spiked to nearly 240,000. However, that means only several percent of investors apparently were spurred to take action, since the average monthly number of such transactions is about 120,000 and some investors order more than one transaction when reallocating their investments. The August number was the highest in more than a year, but not far above the 225,000 transfers last December.

In addition to the two bond-oriented funds, the TSP offers a large company U.S. stock fund, a small company U.S. stock fund, an international stock fund, and five “lifecycle” funds that contain mixes of the other funds that vary according to the expected withdrawal date.

Over June, July and August, all down months for the stock funds, TSP investors moved a net $8.7 billion into the most secure fund, the government securities fund, and $1.1 billion into the mixed bond fund. At the end of August the former fund held 45 percent of all TSP investments and the latter fund 7 percent, compared with 40 percent and 6 percent at the end of May.

The second-largest fund, the large company U.S. stock fund, dropped from a 25 percent share of investments to 22 percent in that time.