The three-year rise in mortgage securitization rates, one of the longest in recent history, came to a halt in 2004 as a significant slowdown in refinance activity coupled with a sharp rise in portfolio lending resulted in fewer loans being funneled into the MBS market. According to a year-end analysis by Inside MBS & ABS, the share of new mortgage originations plowed into the MBS market came in at 64.9 percent for all of 2004.…