US stocks resumed trading after the Labor Day holiday with all three major indexes lower as rising oil prices, reported explosions at Iran's Kharg Island and renewed Middle East supply concerns revived inflation and interest-rate fears. The Dow Jones Industrial Average fell 628.18 points, or 1.18%, to 52,786.07, while the S&P 500 lost 0.58% to 7,673.52 and the Nasdaq Composite declined 0.32% to 26,421.41. Semiconductor shares outperformed, with the Philadelphia Semiconductor Index gaining 1.30% as Intel, AMD, Qualcomm, Broadcom and optical-networking stocks advanced, although Nvidia and several other chipmakers fell. Investors turned to upcoming US consumer-price data and Federal Reserve officials' comments for clues on whether higher oil prices would keep rates elevated for longer.