...- J.P. Morgan Mortgage Trust 2021-INV3's issuance is an RMBS securitization backed by investment property residential mortgage loans. - We assigned our preliminary ratings to 12 classes of mortgage pass-through certificates. - The preliminary ratings reflect our view of the transaction's associated structural mechanics, the representation and warranty framework, and the high-quality collateral in the pool among other factors. NEW YORK (S&P Global Ratings) July 26, 2021--S&P Global Ratings today assigned its preliminary ratings to J.P. Morgan Mortgage Trust 2021-INV3's mortgage pass-through certificates (see list). The certificate issuance is an RMBS securitization backed by first-lien, fixed-rate, fully amortizing investment property mortgage loans secured by one- to four-family residential properties, condominiums, and planned-unit developments to primarily prime borrowers. The preliminary ratings are based on information as of July 26, 2021. Subsequent information may result in the assignment...