Last year’s dramatic decline in refinance activity amidst a very strong home purchase mortgage market helped trigger a dip in the jumbo share of the residential mortgage market, a new Inside Mortgage Finance analysis of recently released Home Mortgage Disclosure Act data reveals. According to the analysis, the jumbo share of the market slipped to 24.2 percent in 2000. This was not only down slightly from the 25 percent jumbo market share found in 1999,