The U.S. Treasury’s rescue plan for Fannie Mae and Freddie Mac could cost taxpayers $25 billion, congressional researchers said on Tuesday. Evidence is also mounting that problems at the two companies are helping push up interest rates for homebuyers. According to the Financial Times, “U.S. mortgage rates have hit their highest levels in about a year amid rising Treasury yields and growing fears among investors that Fannie and Freddie will cut back their purchases of home loans and mortgage securities.”