US stock futures switched between small gains and small losses on Monday, with markets closed for the Labor Day holiday.

    Futures for the Dow Jones Industrial Average edged down by 4 points, or less than 0.1%, to 18,476, after trading slightly higher earlier. Futures for the S&P 500 index dipped b    y 1.25 points, or less than 0.1%, to 2,176.75, while those for the Nasdaq-100 index shed 8.50 points, or 0.2%, to 4,786.75.