The fastest-growing sectors of the mortgage market during the second quarter of 2015 were jumbo loans and government-insured production, according to a new Inside Mortgage Finance ranking and analysis. The conventional-conforming segment remains the biggest piece of the mortgage market, accounting for 52.8 percent of originations during the second quarter. Back in early 2013, when refinance activity accounted for three of every four new home loans, the conventional-conforming share was 68.1 percent. Lenders generated...[Includes two data charts]