Nearly every single mortgage bond issued today comes from either Fannie Mae, Freddie Mac or Ginnie Mae.

Since there is very little private residential mortgage-backed securities issuance, the levels outstanding continue to drop.

It's finally to a point, according Howard Esaki, Global Head of Structured Finance Research at Standard & Poor's, where agency debt is eclipsing the once massive private market.

"The rise in agency RMBS outstanding almost offset the decline in the non-agency sector in Q2, according to Fed flow-of-funds data," Esaki said. "$10trn in home mortgage debt remained outstanding, down $53bn q/q, $254bn y/y, and off more than a $1.2tn from YE 2007. The share held by ABS issuers was off $46bn q/q, $180bn y/y, and $1.2tn from the 2007 peak. Agency MBS increased $40bn q/q, and $120bn y/y."