The housing problem, he had thought, was limited to the increase in subprime loans to borrowers with poor credit. Although the subprime market had mushroomed to $2 trillion, it was still just a fraction of the overall $14 trillion U.S. mortgage market. But that analysis did not take into account a number of other critical factors, such as the fact that the link between the housing market and the financial system was further complicated by the growing use of exotic derivatives.
