Earlier this year Prem Watsa, the gunslinging chief of Fairfax Financial, had $341 million riding on a hunch that dozens of brokers, banks and insurers could struggle paying their debts. Watsa has a history of making a killing on bearish bets. He sold half the company's stock holdings before the 1987 crash and bought puts against the S&P 500 before the index fell in 2000. But as summer began, his latest wager had produced nothing but losses.

Then the credit markets seized up, and investors began clamoring for the Toronto insurer's collection of credit default swaps, basically insurance against bond defaults. Prices climbed. By the end of July Fairfax's swaps were worth $537 million, up 170% in a month.

The winners and losers from the credit crunch are still being tallied, but one thing is clear: Some smart investors won big, and suddenly.