US futures slightly lower as market volatility continues By: CNBC.com News December 11, 2018 at 03:42 AM EST U.S. stock index futures pointed to a fairly flat open on Tuesday as stocks take a breather after a wild session in the previous trading day. Read More >> Related Stocks: Dow Industrials SPDR Nasdaq ETF S&P 500 Ishares Core ETF SPDR S&P 500 ETF Trust