JPMorgan Mortgage Acquisition Corp. is an “above average” aggregator of jumbo mortgages, according to a rating issued last week by Moody’s Investors Service. “JPMMAC’s strengths include the financial strength of its parent company and extensive controls which ensure consistent production quality,” the rating service said. Chase’s jumbo conduit operation buys closed loans from approved sellers and doesn’t originate mortgages. Of the approximately 9,800 jumbos ...