But in 2009, Fitch's expectations fell for certain first-lien residential mortgage-backed securities (RMBS), and because of this, Fitch increased the expected loss estimates related to first-lien RMBS exposures, the rating agency said. "We are pleased that Assured Guaranty Corp. and FSA remain in the double-A rating category, a designation indicative of significant financial strength," said Assured Guaranty's president and CEO Dominic Frederico in a statement. "We believe the one-notch rating downgrades primarily incorporate Fitch's stress loss estimates based on an extremely pessimistic view of the future performance of residential mortgage exposures and point out that Fitch noted our ability to mitigate potential future losses and improve rating agency capital." Loss estimates are outpacing growth in paying resources, putting more pressure on Fitch's revised performance expectations.