The performance of US prime jumbo loan performance within residential mortgage-backed securities (RMBS) slipped again in January as serious delinquencies (60+ days past due) rose for the 32nd consecutive month and edged closer to 10%, according to the latest market commentary from Fitch Ratings. Prime jumbo loan delinquencies began to rise in Q207 but accelerated since then. In 2009, the rate of delinquency nearly tripled during the year. The serious delinquencies rose to 9.6% in January from 9.2% in December. “The new year has brought no relief from declining jumbo loan performance,” said Fitch managing director Vincent Barberio. “The trend line for delinquencies indicates the 10% level could be reached as early as next month.” A jumbo mortgage has an initial principal amount above the $417,000 conventional loan limit set by Fannie Mae (FNM) and Freddie Mac (FRE). In higher-priced markets the limit is $729,750, and, in October, appropriations committees in both the House and Senate proposed an extension of the limit through 2010. Fitch indicated delinquency rates on pre-2005 prime jumbo RMBS vintages are still lower than recent vintages. But seasoned RMBS pools have deteriorated over the last year, rising to 4.3% in serious delinquency from 1.8%. Of all prime jumbo senior RMBS classes issued before 2005, about 40% are under a negative rating outlook due to weak collateral performance, despite only 5% having experienced downgrades so far. The roll rate of prime jumbo borrowers that fell into delinquency declined slightly to 1.2% for January from the seasonal high of 1.3% in December, Fitch said. California spearheaded the rising delinquencies, jumping to 11.3% in January from 10.8% a month earlier. The state represents 44% of the $381bn prime jumbo RMBS market. Four other states rounded out the top five in terms of highest volume of prime jumbo loans outstanding. New York, which represents 7% of the market, saw delinquencies rise to 6.1% from 5.8% the month before. Florida, representing 6% of the market, rose to 16.6% delinquent, from 16%. Virginia, representing 5% of the market, jumped to 5.6% delinquent from 5.4%. And New Jersey, representing 4% of the market, grew to 7.4% delinquent, from 7.1%. Write to Diana Golobay.