Moody’s Investors Service proposed a significant overhaul to ratings for non-agency MBS servicers late last week. Among other new metrics, the rating service is planning to incorporate performance data from mortgages serviced for the government-sponsored enterprises. Currently, servicers submit loan-level portfolio data to Moody’s as part of the rating service’s “servicer quality assessments.” The data would be augmented with data from securitization trusts, which is available more quickly, as well as GSE performance data “as needed.” Data from securitization trusts will receive...