Mortgage applications increased 21.7 percent from one week earlier, according to data from the Mortgage Bankers Association's Weekly Mortgage Applications Survey for the week ending Aug. 5, 2011. The Market Composite Index, a measure of mortgage loan application volume, increased 21.7 percent on a seasonally adjusted basis from one week earlier. On an unadjusted basis, the Index increased 20.9 percent compared with the previous week. The Refinance Index increased 30.4 percent from the previous week. The seasonally adjusted Purchase Index decreased 0.9 percent from one week earlier. The unadjusted Purchase Index decreased 1.2 percent compared with the previous week and was 4.9 percent higher than the same week one year ago. The refinance share of mortgage activity increased to 75.6 percent of total applications from 70.1 percent the previous week. The adjustable-rate mortgage (ARM) share of activity decreased to 6.1 percent from 6.6 percent of total applications from the previous week. "Amid substantial market turmoil last week, mortgage rates dropped to their lowest levels of the year, and refinance applications jumped more than 30 percent to their highest levels of the year," said Mike Fratantoni, MBA's VP of research and economics. "Over the past month, refinance application volume has increased by 63 percent. Refinance applications for jumbo loans increased by almost 75 percent relative to last week. Despite these low mortgage rates, applications for home purchase have remained little changed through the summer." The four week moving average for the seasonally adjusted Market Index is up 9.7 percent. The four week moving average remained unchanged for the seasonally adjusted Purchase Index, while this average is up 13.7 percent for the Refinance Index. The average contract interest rate for 30-year fixed-rate mortgages decreased to 4.37 percent from 4.45 percent, with points increasing to 1.07 from 0.78 (including the origination fee) for 80 percent loan-to-value (LTV) ratio loans. The effective rate also decreased from last week. The average contract interest rate for 15-year fixed-rate mortgages remained unchanged at 3.52 percent, with points decreasing to 0.96 from 1.02 (including the origination fee) for 80 percent LTV loans. The effective rate also decreased from last week.