Due diligence can be a more significant factor in the rating of a jumbo mortgage-backed security than the representations and warranties on the deal, according to Kroll Bond Rating Agency. However, major investors in non-agency MBS have expressed concerns about due diligence on new deals along with the adequacy of disclosures. At a structured-finance investor conference hosted by KBRA this month, the rating service noted that it doesn’t adjust expected losses or credit enhancement for variations in ...