Fannie Mae and Freddie Mac controlled about 90% of the secondary mortgage market.

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Lenders thought they could make money on a loan even if the consumer could not pay back that loan, either by banking on rising housing prices or by off-loading the mortgage into the secondary market.

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Increasingly, says Kathleen Engel, at the Cleveland-Marshall College of Law in Ohio, borrowers are looking for redress further along the lending chain, bringing claims against participants in the secondary market for the predatory acts of mortgage brokers and originators.

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Now, with real estate rebounding, there has been a comeback of the secondary market, in which mortgage-backed securities are sold to investors.

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Mortgage companies make loans and then sell them into the secondary market, freeing up capital to make more loans.

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If a lender makes a mortgage loan, he or she can repackage that obligation with other loans and sell it on the secondary market to reduce the risk.

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