According to the MBA's latest Weekly Mortgage Applications Survey, mortgage application volume dropped 3.6 percent in the week ended July 20 -- the Market Composite Index used to track aggregate application activity dropped to 609.0, near a 5-month low. A steep drop in purchase applications appears to be to blame here, with the Purchase Index dropping 5.0 percent from one week earlier; refinance applications dropped less sharply, falling 1.6 percent, according to the MBA. Refinance share of mortgage activity increased to 38.5 percent of total applications from 37.7 percent the previous week, reflecting moreso the drop in purchase applications than an increase in refinance applications. ARM share of activity remained unchanged at 21.0 percent of total applications from the previous week, the MBA said. Update: Reuters caught on to the trending information here, noting that the composite index is the lowest its been since mid-February.