Fannie Mae and Freddie Mac will try to transfer the credit risk on 90 percent of their mainstream mortgage business in 2016 under new marching orders from the Federal Housing Finance Agency, but next year’s activity may end up being less than the 2015 total. The FHFA in the past has set credit-risk transfer goals based on specific dollar amounts. But next year’s target is to sell some of the credit risk on nearly all of the fixed-rate mortgages the two government-sponsored enterprises buy that have loan terms exceeding 20 years and loan-to-value ratios over 60 percent. Activity in the dwindling Home Affordable Refinance Program will be excluded. In the first 11 months of 2015, the two GSEs securitized...