Although they're backed mainly by installment contracts signed by people who can't even qualify for a credit card, most of these bonds have been rated investment grade. Many have received the highest rating: AAA.
That's because rating firms believe that with tens of thousands of loans lumped together, the securities are safe even if some of the loans prove worthless.
That's because rating firms believe that with tens of thousands of loans lumped together, the securities are safe even if some of the loans prove worthless.

