Fitch Downgrades Over $3B of Subprime MBS

More than 100 classes of subprime residential mortgage-backed securities with outstanding balances totaling over $3 billion were downgraded by Fitch Ratings on Aug. 2.Fitch also affirmed the ratings on classes with outstanding balances of more than $20 billion. Among the downgrades were: 47 classes from 10 issues of Morgan Stanley mortgage pass-through certificates; 46 classes from nine issues of J.P. Morgan Mortgage Acquisition Corp. asset-backed mortgage pass-through certificates; 20 classes from three ACE Securities mortgage pass-through certificates; and 19 classes from three issues of Societe Generale mortgage pass-through certificates. The rating actions were based on changes to Fitch's subprime loss forecasting assumptions, which "better capture the deteriorating performance of pools from 2006 and late 2005 with regard to continued poor loan performance and home price weakness," the rating agency said. Fitch reported that as of the end of the day on Aug. 2, it had downgraded 291 such classes with an outstanding balance of $5 billion and affirmed the ratings on 526 classes with an outstanding balance of $46 billion.