Redwood Trust’s four non-agency mortgage-backed securities – the latest of which was issued last week – have been generally well received by MBS investors. However, some investors, potential issuers and even the rating services have raised concerns regarding the non-agency MBS ratings process, both for Redwood and for other potential securitizers. A senior official at one of the rating services suggested to Inside Nonconforming Markets that ratings shopping is still occurring, and that the Redwood deals have been rated by the firms with the lowest credit-enhancement requirements ...