Performance of jumbo mortgages originated before 2005 is declining, bucking a trend among non-agency mortgages, according to Fitch Ratings. Most of the remaining pre-2005 jumbo borrowers have been unable to refinance. Many high-quality mortgage borrowers are refinancing to take advantage of record-low interest rates, leaving the remaining mortgage pools increasingly concentrated with borrowers unable to refinance, said Grant Bailey, a managing director at Fitch. More than 93.0 percent of the roughly ...