With refinance transactions accounting for three out of four home mortgages financed through agency programs in the first half of 2012, most top lenders securitized significant volumes of refi loans through Fannie Mae, Freddie Mac and Ginnie Mae.But a new Inside Mortgage Finance analysis and ranking reveals that a number of lenders man-aged to focus on the fast-growing home purchase-mortgage market during the first half of 2012. At the top of that list was Pulte Mortgage, the subsidiary of a national homebuilding company, where pur-chase-money mortgages accounted for 99.0 percent of...