NEW YORK–(BUSINESS WIRE)–Kroll Bond Rating Agency (KBRA) assigns preliminary ratings to twenty-five classes of mortgage pass-through certificates from J.P. Morgan Mortgage Trust 2019-1 (JPMMT 2019-1), a prime RMBS transaction. JPMMT 2019-1 contains both prime jumbo (33.0%) and conforming (67.0%) collateral to borrowers with prime attributes. The JPMMT 2019-1 mortgage pool is composed of 1,707 first-lien mortgage loans with an aggregate principal balance of $978,118,609 as of the cut-off date.