Fitch Ratings is thinking of reducing the ratings of almost $160 billion in securities supported by alt-A mortgages. Alt-A mortgages are loans made without proof of income, or with borrowers with minor credit issues. Fitch has already put over 471 security transactions involving residential mortgages on a negative watch list as the odds of homeowners defaulting on increasing is rising. Similar reductions have already been done on securities supported by subprime loans, helping to contribute to the almost $160 billion write down cuts made by banks and lenders.

Fitch´s managing director, Glenn Costello, has said that "Accelerating home price declines partly due to the dramatic contraction in... the mortgage markets has been the primary catalyst of the alt-A performance downturn,".

Fitch will be reviewing over #10 billion in subordinate alt-A backed securities and then look at ones with AAA ratings. They hope to end the review at the end of April.