While Fannie Mae and Freddie Mac have scaled back their purchase of subprime mortgages on a flow basis, the two GSEs remain heavily involved in the market as investors in mortgage-backed securities, a new analysis by Inside the GSEs reveals. Through the end of June, Fannie and Freddie combined to purchase some $33.27 billion in classes of subprime mortgage security deals specially structured to contain loans with balances below the $322,700 conforming loan limit.