" There was more than one way to think about Mike Burry’s purchase of a billion dollars in credit default swaps. The first was as a simple, even innocent, insurance contract. Burry made his semiannual premium payments and, in return, received protection against the default of a billion dollars’ worth of bonds. He’d either be paid zero, if the triple-B-rated bonds he’d insured proved good, or a billion dollars, if those triple-B-rated bonds went bad. But of course Mike Burry didn’t own any triple-B-rated subprime mortgage bonds, or anything like them. He had no property to “insure” it was as if he had bought fire insurance on some slum with a history of burning down. To him, as to Steve Eisman, a credit default swap wasn’t insurance at all but an outright speculative bet against the market—and this was the second way to think about it. "

― Michael Lewis , The Big Short: Inside the Doomsday Machine