For the first time since October 2008, Moody’s Investors Service upgraded two top private mortgage insurance companies to investment grade due to strong performance of new insurance written, cost savings and fewer losses. However, risk factors, including proposed capital regulations from the National Association of Insurance Commissioners, could adversely impact the ratings. Mortgage Guaranty Insurance Corp. and Radian Guaranty now have Baa3 ratings from Moody’s, although other rating servicers appear disinclined to follow. Both MIs continue to be rated below investment grade by Standard & Poor’s. The improved ratings come...