Stocks finished mostly lower, running out of steam after August gains that were the largest monthly increases for the Dow and S&P 500 since February.
A better than expected reading on U.S. manufacturing failed to spark an advance, and analysts said the result probably was priced into the market last week.
The losses came on the first trading day of September, which has historically been a bad month for stocks.
Volume remained on the light side, with just 578M shares traded at the NYSE.
The energy sector was the day's worst performer, with Chevron slipping 1.5% and Exxon tumbling 1%, followed by the utilities sector.
Dollar strength was behind the day's weakness in commodities, where Nymex oil prices slid 3.1%, natural gas dropped 4.2% and gold fell 1.7%.
Treasury prices tumbled, with the 10-year note settling at its low for the day and its yield jumping 7 bps to 2.42%.