Under the CFPB proposal, which aims to establish a level playing field between the GSEs and the non-agency market, most loans will still be QMs, but there might be fewer incentives to sell the loans to the GSEs.

In his semiannual report to Congress on Tuesday, Fed Chair Jerome Powell described the MBS market as "vital to the flow of credit in the economy."

Instead of larger, multi-issuer uniform MBS pools, FHFA wants seller/servicers to closely monitor the prepayment speeds of their broker/correspondent channels to ensure closer alignment of Fannie/Freddie pools.