Mortgage rates held steady Wednesday as mortgage-backed securities markets drifted ahead of today’s 10-year Treasury auction. No economic data will be released today. Treasury Secretary Tim Geithner extended the controversial $700 billion TARP fund until October 3, 2010. The TARP’s authorization had been due to expire at the end of 2009. The Mortgage Bankers Association weekly purchase activity index rose by 4%, while the refinancing activity index increased by 11%. Average reported 30-year fixed rates for the prior week rose to 4.88% (with 0.7 points) from 4.79%.