Stock market today: Dow, S&P 500, Nasdaq futures extend losses amid US-Iran tensions Yahoo FinanceWall Street indexes slip as oil prices rise, retail results awaited ReutersMarkets News, Aug. 17, 2026: US Stocks Start Week Lower, Oil Prices Rise; Memory Shares Outperform InvestopediaStock Market Today: Dow Slides As This Key Yield Hits 19-Year High; Warren Buffett Stock Falls (Live Coverage) Investor's Business DailyStock futures are little changed after Wall Street starts the week with losses, hurt by higher oil prices and rising yields: Live updates CNBC