In the middle years of disco and the early days of securitisation, mortgage-backed bonds were on balance sheet and government-sponsored enterprises (GSEs) were a factor, albeit not a dominant one, in the market. Over time, securitisation became an off-balance-sheet financing approach that provided enormous leverage, and GSEs became central to the growth of the market.

Since the advent of the financial crisis, GSEs have purchased at least 70% of residential originations in the United States. In early February 2011, the Department of the Treasury and the Department of Housing and Urban Development published a report outlining a three-pronged approach to restructure the US. housing finance system.

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