Fannie Mae and Freddie Mac saw a modest uptick in production of single-family mortgage-backed securities in July, as 2017 activity remained slightly above last year’s levels. The two GSEs issued $71.84 billion of MBS last month, a 3.7 percent increase from June. That brought year-to-date volume to $479.77 billion, including securitization of modified loans, a slim 1.1 percent increase compared to the first seven months of 2016. The GSE market continued to shift dramatically from refinance loans to purchase mortgages. Refi loans accounted for just 33.4 percent of Fannie and Freddie business in July after ending 2016 with 55.4 percent of GSE business.