Nonprime mortgages and mortgage-backed securities caused a significant portion of the losses suffered by the government-sponsored enterprises since 2008. However, the nonprime assets that the GSEs have held on to have seen lower credit losses and even profits recently due to improving home prices and investor demand for vintage MBS. Fannie Mae and Freddie Mac have allowed their non-prime exposure to run off since 2008, rather than selling the assets. As of the end of the third quarter of 2012 ... [Includes one data chart]