U.S. stocks flat ahead of ISM data

U.S. stocks traded almost unchanged as investors returned from a three-day weekend and awaited the release of a closely watched manufacturing survey. The Dow Jones Industrial Average fell  0.1%, to 13,077.; the Standard & Poor 500 Index edged 0.02% higher, to 1,403.80, while Nasdaq 100 futures lost  0.04%, to 2,770.00.