FedEx

Why it's important: FedEx (FDX) is a barometer of business activity in particular because of its strength in document shipping.

Outlook: U.S. overnight envelope shipping volume slid 10% in the quarter ending in August, according to FedEx, the sharpest drop in any category in two years. (Data from September were not available, a spokesman said.) In the company's earnings call Sept. 18, Chairman Fred Smith noted that the overnight document business is tied to housing, mortgages, and financial services. Executives also cited the economy as a factor behind a shift toward ground shipping as customers seek cheaper options.