The Department of Housing and Urban Development tapped Bob Ryan, formerly the chief risk officer at the Federal Housing Administration as its acting commissioner, replacing David Stevens. Stevens departs the FHA Thursday and will run the Mortgage Bankers Association. During his tenure as commissioner of the FHA, he created the chief risk office and placed Bob Ryan in charge in October 2009. Ryan held senior positions at Freddie Mac capital markets, single family pricing and the as the company’s president. Ryan has spent 26 years in the mortgage market. As the chief risk officer, Ryan expanded the FHA’s ability to assess financial and operational risk to its fund and perform more sophisticated data analysis. He will lead the FHA during a critical time. Its share of the market grew from 3% in 2005 to 37% in 2009 and remains a dominant player. It has grown so large that Congress is considering new changes to housing finance that would wind down the FHA involvement and return more market share to the private sector. Write to Jon Prior. Follow him on Twitter @JonAPrior.