The market tumult in recent weeks has been a boon for exchange-traded funds.

In a market that has been permeated by elevated levels of volatility now for the better part of two months, investors have been flocking to the stability and safety of exchange-traded funds.

“When looking at ETF volume as a percentage of the overall market volume, we saw an uptick in that in August,” said Stuart Rosenthal, chief executive officer of Factor Advisors, a New York asset management firm. “It was about 47 percent of all stock exchange volume in August, that is much higher than what was observed year to date January through July, when it was 34% of overall volume.”

The Chicago Board Options Exchange’s Market Volatility Index, or VIX, has been trading at elevated levels for the past two months, reaching as high as 48 on Aug. 8, as the markets reacted to the debt ceiling situation and the Standard & Poor’s downgrade of U.S. debt. It then hovered around the mid-30s in the following weeks, without dropping to the 20s. The last time the VIX was under 30 was Aug. 3. As of Sept. 22, it has been trading over the 40 mark again. The VIX, also known as Wall Street’s “fear gauge,” measures the implied volatility of the S&P 500 index.

“Heightened volatility will be the norm for the foreseeable future until the European credit situation is straightened out,” said Rosenthal. “We’re observing a lot of movement out of funds in Europe, and into dollar-denominated assets. Until the Greece situation is resolved, there will continue to be uncertainty in the marketplace, and uncertainty and volatility goes hand in hand.”

According to BATS Global Markets, equity trading volume was on the decline since reaching a peak of nearly 18 billion shares on Aug. 8, declining by more than half during the following week, with about 7.3 billion shares changing hands on Aug. 17. About 10.6 billion shares were traded per day on average in August. For the month-to-date in September, ADV has fallen to about 8.4 billion. Volume once again shot up to over 13 billion shares traded on Sept. 22, which was the most volume seen since Aug. 10.

“What is interesting to note, by our calculations, on (Sept. 22), when there was a surge in volatility across the board, ETF volume stayed around its 2011 average, at 36 percent of all exchange volume. Contrary to what many think, it’s not always the case where ETF volume surged relative to the overall market.”