U.S. stock markets faced significant declines as the Dow Jones Industrial Average tumbled by nearly 500 points, driven by fears surrounding escalating tensions in the Middle East and surging Treasury yields that climbed above 4%. The rise in oil prices added to market pressures, with investors reconsidering their expectations for rate cuts from the Federal Reserve. Major indexes, including the S&P 500 and Nasdaq, also experienced losses as the market braced for upcoming economic data and earnings reports. Wall Street's cautious sentiment was compounded by Powell's remarks that reset market expectations, further impacting trading activities.