Fannie Mae this week joined Freddie Mac in announcing a front-end credit-risk transfer pilot that will use additional levels of private mortgage insurance, but the so-called deep MI option looks like a long shot. “Credit-risk transfer is the next big thing, and though we’re already three years into it, it’s still very much a work in progress,” said Donald Layton, Freddie’s CEO, during the annual convention of the Mortgage Bankers Association in Boston this week. “About 50 percent of the credit risk that’s coming in is...