Fannie, Freddie Slashed CMBS Holdings in 2013. Fannie Mae and Freddie Mac continued to sell off their holdings of non-agency commercial mortgage-backed securities as the preferred strategy for meeting their regulator's demand that the two GSEs accelerate the reduction in their retained mortgage portfolios.The two GSEs reduced their CMBS holdings by 51.4 percent over the course of 2013, according to an analysis of year-end financial statements.