US futures pull back ahead of the open amid geopolitical developments By: CNBC.com News September 11, 2018 at 04:35 AM EDT U.S. stock index futures fluctuated ahead of Tuesday's open, as investors focused on geopolitics. Read More >> Related Stocks: Dow Industrials SPDR Nasdaq ETF S&P 500 Ishares Core ETF SPDR S&P 500 ETF Trust