" The big fear of the 1980s mortgage bond investor was that he would be repaid too quickly, not that he would fail to be repaid at all. The pool of loans underlying the mortgage bond conformed to the standards, in their size and the credit quality of the borrowers, set by one of several government agencies: Freddie Mac, Fannie Mae, and Ginnie Mae. The loans carried, in effect, government guarantees; if the homeowners defaulted, the government paid off their debts. "

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