An affiliate of Western Asset Management Co. is set to issue one of the largest post-crisis non-agency mortgage-backed securities. The planned $1.25 billion issuance differs in a number of ways from deals with non-qualified mortgages from other issuers. Arroyo Mortgage Trust 2018-1 will be the first non-QM MBS from WAMC. The firm has been stockpiling non-QMs and other non-agency mortgages since the end of 2014. Loans in the pending MBS have seasoned for an average of ...