The guaranty fees charged by Fannie Mae and Freddie Mac are close to hitting a tipping point where non-agency mortgage-backed security issuance will be the more economic execution for new originations, according to some non-agency participants. “If the non-agency pricing is improving and the GSE pricing is worsening, at some point you’re going to hit a tipping point,” Luke Scolastico, a vice president at Credit Suisse, said last week at a panel discussion hosted by the American Securitization Forum ...