CSFB MBS Classes Downgraded

Fourteen tranches of mortgage-backed securities issued by CSFB Adjustable Rate Mortgage Trust in 2004 and 2005 have been downgraded by Moody's Investors Service, and seven tranches have been placed on review for possible downgrade.Moody's also downgraded six tranches of CSFB Home Equity Pass-Through Certificates, series 2005-1, which is backed by first-lien subprime mortgage loans. The actions were based on an analysis of the credit enhancement levels provided by excess spread, overcollateralization, and subordinate classes relative to expected losses, Moody's said. The collateral for the tranches issued by CSFB Adjustable Rate Mortgage Trust consists of first-lien alternative-A mortgage loans.