Mortgage rates continued the retreat, with the average conforming 30-year fixed mortgage rate falling to 6.42 percent. According to Bankrate.com's weekly national survey of large lenders, the average 30-year fixed mortgage has an average of 0.45 discount and origination points.

The average 15-year fixed rate mortgage popular for refinancing declined to 5.95 percent, while the average jumbo 30-year fixed rate held steady at 7.64 percent. Adjustable mortgage rates were mixed, with the average 1-year ARM rising to 6.21 percent and the average 5/1 ARM holding at 6.05 percent.

Mounting worries about the economy and the health of the financial system drew investors out of stocks and into the relative safety of bonds. Mortgage rates are closely related to yields on risk-free Treasury notes. Amid the nervousness, mortgage rates touched lows not seen since the first week of June. But inflation remains an issue, as evidenced by the Consumer Price Index for June, and will continue to spar with weak economic growth as the factors influence the direction of mortgage rates. The up and down yo-yo of mortgage rates seems likely to continue, with rates fluctuating within a range.

Mortgage rates have been on a wild ride since the beginning of the year. The average 30-year fixed mortgage rate was as low as 5.57 percent in January, meaning that a $200,000 loan would have carried a monthly payment of $1,144.38. But at today's rate of 6.42 percent, a $200,000 loan would mean a monthly payment of $1,253.63.