Reforming the housing-finance system under the plan from Sen. Bob Corker, R-TN, includes having at least a handful of guarantors, winding down the GSEs and establishing a mortgage insurance fund with private capital, according to a leaked draft making the rounds this week. The 80-page document seeks to promote competition in the marketplace by having five or six guarantors of conventional mortgage-backed securities, with none of them getting more than 20 percent to 25 percent of the market. Those new guarantors would be expected to launch within two years. Section 809 of the legislation spells out that “as promptly as practicable” the FHFA can greenlight Fannie Mae and Freddie Mac to “sell or transfer” their assets.