Some of the world's most successful hedge fund managers seem to wish they had followed the old adage "sell in May and go away."

Speaking at a conference in New York on Wednesday, one top-rated stock picker after another shared concerns about the state of the world economy amid a sharp correction in the stock market that started a month ago.

"As I look at the current investment climate I have to tell you I'm worried," said Jonathon Jacobson who founded hedge fund firm Highfields Capital. His biggest concern — U.S. lawmakers who he says are creating a hostile environment for business.

"What I worry about are the clowns and the climate in Washington," Jacobson said, adding "there is no leadership on either side of the aisle."

For Daniel Arbess, a partner at Perella Weinberg Partners and the portfolio manager of its Xerion Funds, it is more than the climate that is giving him pause.

"The very foundation of the economy is shifting under our feet," he explained.

With the euro crumbling, worries about the safety of sovereign debt rising, Europe hurtling toward a full-blown financial crisis, and U.S. markets taking investors on a roller coaster ride in recent weeks, some managers acknowledged the pain they have suffered themselves.

David Tepper, whose Appaloosa Management gained 130 percent last year on bets that ailing financial stocks would recover, joked about how much money he lost this month.

"We are a $13 billion hedge fund," Tepper said pausing for effect at the Ira Sohn Conference, which raises money to fight pediatric cancer. "At the start of the month we were a $14 billion hedge fund. But what the hell. What are you going to do?"

Current fears about what might happen next added a somber note to an otherwise festive occasion where more than 1,000 investors from around the globe gathered to hear some of the world's most successful investors reveal their thoughts.

Sam Zell, chairman of Equity Group Investments, LLC, warned the audience that whoever doesn't adapt to fast changing conditions may not be here next year.

His stern tone prompted some audible gasps as well as snickering in the crowd.

Coming so soon after the 2008 financial crisis, many managers are finding current conditions especially difficult to explain, and more importantly how one adjusts to them.

Many questions were posed: Is this a repeat of the crisis or possibly something even worse? Will Europe's common currency survive? And what are investors to do in an age where simply purchasing stocks and bonds is probably not enough to secure a comfortable retirement.

"How should we decide whether these issues are real or just the bogeyman," asked Larry Robbins, CEO of Glenview Capital Management. "No one knows," he added, not very reassuringly.

With such uncertainty surrounding the future of world markets, a quick fix seemed equally clouded. Robbins for one laid out three scenarios:

Investors can put assets into cash, buy safer corporate bonds or pick stocks selectively, choosing the ones that will grow no matter what happens to currencies or the economy.