(CNBC) Stock futures were flat in overnight trading on Monday as Wall Street gets set to kick off the holiday-shortened week with the S&P 500 at a record high. Futures on the Dow Jones Industrial Average rose just 30 points. S&P 500 futures were little changed and Nasdaq 100 futures dipped less than 0.1%. U.S. markets remained closed for the July 4 Independence Day holiday.