With the Federal Reserve expected to raise its benchmark overnight lending rate this year, interest rates on new mortgages are also projected to go up. Higher rates on mortgages are likely to cause a significant decline in prepayments on post-crisis jumbo mortgages and will increase default risk, according to Morningstar Credit Ratings. Within the first 12 months of origination, prepayment rates on post-crisis jumbos included in non-agency mortgage-backed securities have ...