The expected increase in interest rates on some previously modified home mortgages is a slight credit negative for RMBS performance because these loans will re-default at a higher rate, according to analysts at Moody’s Investors Service. However, higher default rates will have only a modest effect on subprime and Alt A RMBS, because only a small percentage of outstanding subprime and Alt A mortgage loans are positioned to experience future rate step-ups. In their research, the analysts found that subprime and Alt A modified loans become delinquent more frequently after a rate step-up. “Modified subprime and Alt A loans with a demonstrated performance history of four to five years become delinquent at a significantly higher rate after a step-up in interest rates than do loans of a similar type and vintage that have not stepped up,” said the analysts in a new report released this week. According to their data, in July 2015, only 2 percent of the modified re-performing subprime loans became...