Moody’s Investors Service downgraded the ratings of 49 tranches and confirmed the ratings of four tranches from 15 RMBS deals that are backed by prime jumbo loans that were issued by Wells Fargo MBS from 2005 to 2008. The collateral backing these offerings comprise mostly first-lien, ARM, prime Jumbo residential mortgage loans. The rating agency’s actions were caused by the rapidly deteriorating macroeconomic conditions as well as jumbo pool performance. These actions reflect Moody’s updated loss expectations on prime Jumbo pools issued from 2005 to 2008.