Paul Jackson at Housingwire.com reports:

On the heels of the Treasury’s latest plan to work with private investors to purchase private-party RMBS, Fitch Ratings said Monday afternoon that it had revised its projected cumulative loss estimates for 2005-2007 vintage U.S. prime RMBS transactions — in other words, more downgrades are coming.

Why defaults are surging among prime borrowers has less to do with the mortgage instrument, as was the case early in the mortgage crisis, than with more traditional risk factors tied to declining property values and rising unemployment. For example, Fitch said it found that loans with multiple risk attributes such as limited income documentation and second-liens, are defaulting at rates approximately three times that of loans without those characteristics.

Negative equity, too, is a still-emerging problem: borrowers with negative equity in some recent vintage mortgage pools are approaching 50 percent, the rating agency said. Borrowers with no remaining equity are defaulting at a rate three times greater than their equity-holding counterparts.

Continuing deterioration in what used to be prime credit means the assets Giethner’s plan is aimed at removing from banks are growing faster than PIMCO  can say, “We intend to participate and do our part to serve clients as well as promote economic recovery”.