Fannie Mae and Freddie Mac issued $74.10 billion of single-family mortgage-backed securities during May, down 8.0 percent from April, a new Inside the GSEs analysis reveals. The purchase-mortgage market picked up some last month, but not enough to offset a sharp 15.7 percent drop in the volume of refinance loans securitized by the GSEs. Purchase-mortgage business was up 7.2 percent from April and reached a combined $28.25 billion – the highest monthly volume since the end of last year’s homebuying season in October. For the first five months of 2015, purchase-mortgage activity totaled $105.15 billion, up 19.0 percent from the same period last year. Most of the big gain in overall GSE business has come from refinancing, which is up 94.4 percent on a...(charts included)