AlQa'dah 5, 1434, Sep 11, 2013, SPA -- U.S. futures are falling after two straight days of solid gains, with the Standard & Poor's index headed for its strongest weekly percentage increase since mid-July. Dow Jones industrial futures are down 4 points to 15,169. S&P futures have lost 2.2 points to 1,680.20. Nasdaq futures are down 15 points to 3,167.75. Investors may be pausing ahead of retail sales data due from the Commerce Department on Friday. Retailers offer an undefined look at the mood of the American consumer, who's spending drives about 70 percent of all U.S. economic activity. Most economists expect a slight increase in consumer spending for August. On Wednesday, Commerce releases wholesale trade data for July. Economists believe steady sales gains have prompted businesses to restock more aggressively, which could drive economic growth.