Fitch Ratings updated its loss model criteria for non-agency jumbo mortgage-backed securities this month, including new default estimates that vary by origination channel. Other rating services take the origination channel into account when rating new jumbo MBS, but not necessarily to the extent that Fitch has taken. “Fitch has determined that loans originated through a direct retail channel have a lower default risk than those originated through a broker, correspondent or wholesale channel,” the rating ...