After some tightening in the fourth quarter of 2016, issuers of prime non-agency mortgage-backed securities in the first quarter of 2017 largely returned to the underwriting standards typically seen in the sector, according to an analysis by Inside Nonconforming Markets. Some $2.60 billion of prime non-agency MBS was issued during the quarter, spread across six deals, including a $1.03 billion issuance by JPMorgan Chase. Underwriting ... [Includes two data charts]