Standard & Poor’s announced late last week that it updated the criteria for ratings on non-agency MBS with mortgage collateral originated before 2009. The new standards are effective immediately and will result in significantly more downgrades than upgrades, according to S&P analysts. The standards update criteria for credit, cash flows and rating stability, and introduce new methods for analyzing transactions that have fewer than 100 loans remaining in the pool. Vandana Sharma, a managing director and lead analytic manager for U.S. residential MBS ratings at S&P, said the new standards reflect key market trends. “In light of the stabilization of home prices and delinquencies in the U.S. mortgage market, these criteria seek...