The Big Short: Inside the Doomsday Machine Highlight

the synthetic subprime mortgage bond–backed CDO, or collateralized debt obligation. Like the credit default swap, the CDO had been invented to redistribute the risk of corporate and government bond defaults and was now being rejiggered to disguise the risk of subprime mortgage loans. Its logic was exactly that of the original mortgage bonds. In a mortgage bond, you gathered thousands of loans and, assuming that it was extremely unlikely that they would all go bad together, created a tower of bonds, in which both risk and return diminished as you rose. In a CDO you gathered one hundred different mortgage bonds—usually, the riskiest, lower floors of the original tower—and used them to erect an entirely new tower of bonds.