Investing.com – U.S. stock futures were lower Tuesday as global economic worries weighed. The Dow futures and the S&P 500 were both down 0.4% at 07:00 ET. The tech-heavy Nasdaq 100 futures was also off 0.4 %. Government bond yields fell, as the U.S 10-year Treasury hits fresh lows. U.S. May factory orders due; FOMC member William Dudley to speak.