The latest jumbo mortgage-backed security planned by JPMorgan Chase is smaller than other deals recently issued by the firm. J.P. Morgan Mortgage Trust 2018-1 will be a $463.7 million issuance. A similarly structured deal from Chase in December had a volume of $883.8 million, which followed a $911.0 million deal in October. All three MBS share similar characteristics, with Chase as the top contributor and loans that seasoned for an average of three months at the time of issuance ...