As the housing market deteriorated in April 2007, Fannie Mae Chief Executive Officer Daniel Mudd reported to Congress on his company’s health. The firm’s exposure to subprime loans, he told lawmakers, “remains minimal, less than 2.5 percent of our book.”

Within 18 months, U.S. regulators seized the government- sponsored mortgage firm and its smaller sibling, Freddie Mac, after losses on soured loans pushed them to the brink of insolvency. The two firms have drawn more than $150 billion in life support from the Treasury since then.

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