Standard & Poor’s last week updated its criteria for ratings on non-agency mortgage-backed securities with collateral originated before 2009. The standards update criteria for credit, cash flows and rating stability and apply immediately. The rating service said the changes will result in more downgrades than upgrades. This week, S&P placed 16,872 ratings from 3,364 securities with a par amount of $253.95 billion on CreditWatch. About 70.0 percent of the ratings are on watch for potential downgrades ... [Includes three briefs]