Stock Index Futures Little Lower in Pre-Market

September SP500 is trading at 2160.25, down 4.50. September Nasdaq 100 is trading at 4715.00, down 4.75. September Russell 2000 is trading at 1211.50, down 2.00. September Dow Industrial futures are trading at 18341, down 35. Stock index futures are trading choppy and a little lower in early pre-market trading. Market talk about corporate earnings, global headline news and economic data is making the rounds. The Bureau of Economic Analysis is scheduled to release second quarter gross domestic product (GDP) at 8:30 a.m. ET. University of Michigan consumer sentiment is due out at 10:00 a.m. ET.