New York ? Stocks tumbled Wednesday for the third straight session as investors, increasingly adopting a defensive strategy, bailed out of technology and other higher-risk shares. The Dow Jones industrial average shed 160 points and other major indexes also dropped sharply.

Investors have been anticipating a market pullback following a nearly yearlong rally, but their recent eagerness to collect profits ahead of a significant decline may have helped fuel the correction.

“This is the third day in a row of some pretty heavy-duty rotation out of the cyclical stuff into the defensive stuff,” said Scott Wren, equity strategist for A.G. Edwards & Sons. “It’s like a steamroller effect, with a little selling early on, then more and more as anticipation of a correction set in and people decided to lock in some of these profits.”

While most economists believe the recovery is on track, investors have found few bargains on Wall Street lately. Lackluster gains in the labor market and concerns over when the Federal Reserve will move to raise interest rates have contributed to the market’s malaise.

Many traders were looking to today, when the government was to release its weekly report on unemployment claims, and Federal Reserve Chairman Alan Greenspan was to testify before the House Committee on Education and the Workforce.

“The market has definitely hit a point where it’s weighing valuations against the changing tide of monetary policy,” said Kevin Caron, market strategist with Ryan, Beck & Co.