Rates held steady Wednesday ahead of testimony from Fed Chairman Bernanke, a 10-year Treasury auction, and release of the Beige Book, a survey of economic activity by the Fed’s 12 regional banks. The Mortgage Bankers Association weekly purchase activity index fell 5.7% to the lowest level since February 1997. The index is down 35% from 4 weeks ago following the expiration of homebuyer tax credits. Refinance activity fell 14.3%, although mortgage rates remain near record lows.