Stock Market Today, Aug. 31: Stocks Edge Lower as Oil Prices Surge Again

U.S. stock markets declined on August 31, 2026, as surging oil prices above $90 a barrel amid U.S.-Iran military tensions dampened investor risk appetite. The S&P 500 fell 0.33%, the Dow Jones dropped 0.70%, and the Nasdaq edged down 0.12%. Despite the daily decline, the S&P 500 finished August with a 2.6% gain. Energy stocks gained while basic materials and industrials saw the biggest losses. Investors remain cautious ahead of potential Federal Reserve rate hikes in September.