Just when you'd think activist shareholders would be up at arms because of the historic meltdown in stock prices, they appear to have fled the battlefield.

Activist shareholders buy stakes in underperforming companies, giving them voting power so they can agitate for change. The bear market has cut stock prices by more than half to 13-year lows, which seemingly would create an abundance of potential targets for activists.

Yet the number of new activist shareholder cases against companies fell 75 percent in the fourth quarter to just two, according to data from Thomson Reuters. That's well below the 23 new cases in the first quarter of 2007. Activist cases for all of last year fell 44 percent from 61 in 2007.

""It was a big surprise there was such a large drop-off," said Thomson Reuters' Glenn Curtis. Some reasons:

• Severe lack of funding. Some firms, including hedge funds, relied on borrowed money to quickly accumulate stakes to get management's attention, Curtis said. But with banks reluctant to lend, especially for risky ventures, activists have lost backing.

• Retrenching. Suffering big losses themselves, activist shareholders may need to hold on to their own cash rather than use it to make aggressive moves against other firms, said Stuart Gillan, professor of finance at Texas Tech University.

Even Icahn Enterprises, headed by longtime activist Carl Icahn, has shown strain. Shares of the publicly traded firm, which runs investment and real estate businesses, are down 79 percent from their 52-week high. Icahn did not return a call for comment.

Many activists are reluctant to start new battles and want to focus on the ones they already have going, said Chris Clifford, professor of finance at the University of Kentucky.

• Unclear outlook. Activists try to pick targets where they can cause change and then exit the company by selling at a profit. But with so much uncertainty over what types of businesses other investors would be interested in, activists are waiting, said Jonathan Karpoff, professor of finance at the University of Washington.

Many suspect it's only a matter of time before activists resurface. Icahn, for one, last month said he is boosting his position in movie studio Lionsgate and may seek changes to the board.

Meanwhile, individual investors plan to push for change, especially on executive pay, by inserting resolutions for a vote at this year's annual meetings, said Ric Marshall of The Corporate Library. "Shareholders are very unhappy," he said.