The billionaire hedge fund manager Leon Cooperman told an audience of Wall Street insiders on Wednesday that there was a 70 percent probability that Britain would stay inside the European Union. "I don't worry about Brexit," he added. Ben Hunt of Salient Partners, went as far as to call it a "Bear Stearns moment," evoking the investment firm whose collapse in March 2008 was a prelude to the financial chaos that September. Yet even as the most successful hedge fund managers now survey a sea of down markets, panic has not gripped the...