Due-diligence and document-file reviews will key Fitch’s rating of residential MBS backed by re-performing loans and seasoned mortgage loan collateral, based on revised criteria, according to a recent report from Fitch Ratings. Fitch recently finalized its criteria for analyzing re-performing and seasoned loan RMBS to include closer attention to risk factors. Fitch uses its mortgage loan-loss model as well as representation-and-warranty and due-diligence reviews in analyzing the key risk drivers for RPLs. However, since the methodologies currently used by the rating agency were developed with an eye towards newly originated and seasoned performing collateral, RPL pools and some seasoned performing pools purchased in the secondary market are likely to be influenced...