by Calculated Risk on 4/25/2007 03:52:00 PM

From Standard & Poor's: Ratings On 20 Subprime And 32 Alt-A Classes From 2005-Vintage RMBS Deals Put On Watch Neg

Standard & Poor's Ratings Services today placed its ratings on 52 subordinate classes from 45 residential mortgage-backed securities (RMBS) transactions issued in 2005 on CreditWatch with negative implications. The affected classes are rated [from] 'A-' [to] 'B'.

The CreditWatch placements reflect early signs of poor performance of the collateral backing these transactions. ...

Many of the 2005-vintage transactions may be showing weakness because of origination issues, such as aggressive residential mortgage loan underwriting, first-time homebuyer programs, piggyback second-lien mortgages, hybrid ARMs entering their reset periods, and the concentration of affordability loans.

It will interesting to see if there is any impact from the incipient credit crunch on Countrywide Financial and IndyMac Bancorp - they both report tomorrow morning.