Ratings firm DBRS re-rated 549 classes from 52 different U.S. residential mortgage-backed securities deals this week.
The company confirmed most of the prior ratings, while upgrading 63 and downgrading 6 classes.
Another 35 classes within the deals were classified as discontinued re-paids because of prepayments made on the principal balances, the ratings giant said.
"The classes that have been upgraded exhibited positive performance trends that have led to increases in credit support sufficient to withstand stresses at their new rating level or are linked to the rating of corporate entities providing credit support to the tranche or transaction," DBRS advised.
Those that were affirmed maintained a current asset level performance that is in line with current ratings while also possessing the right credit supports.
"The downgrades taken reflect a combination of the continued erosion of credit support in these transactions as a result of negative trends in delinquency and projected loss activity," DBRS advised.
The deals impacted are made up of U.S. ReREMIC deals – most of which are backed by pools of prime and alt-A home loans.