U.S. stocks came under heavier selling pressure Tuesday, with the Dow Jones Industrial Average falling 0.8% to 52,766.88 and closing below its 50-day moving average for the first time since April 10. The break ended a run in which the index had remained above that level every trading day since April 11 and marked its lowest close since July 31. The Dow is now 2.9% below its August 5 record of 54,349.12. The S&P 500 dropped 0.7% to 7,631.47, just 0.8% above its 50-day average, while the Nasdaq Composite lost 1% to 26,099.77, leaving a 0.6% cushion. The breach could encourage technical traders and quantitative strategies to sell, while elevated oil prices, persistent inflation and higher Treasury yields continue to constrain equities. Brent crude rose 2.3% to $92.61 a barrel as conflict between the United States and Iran disrupted shipping through the Strait of Hormuz, a route handling roughly 20% of global crude volumes. The 10-year Treasury yield rose to 4.77% and the two-year yield to 4.37%, while U.S. national debt surpassed $40 trillion two weeks earlier. Analysts are watching whether the 10-year yield approaches 5%, a level that could weigh especially on technology stocks. Investor sentiment moved toward caution, with the CNN Money Fear & Greed Index falling to 49.6 but remaining neutral. Microsoft declined 1.3% and Advanced Micro Devices fell 2.4%. Despite the short-term weakness, the Dow gained more than 1% in August for a fifth straight monthly advance, while the S&P 500 and Nasdaq rose 2.6% and 3.9%. Analysts say the combination of weakening technical signals and recent monthly gains could produce greater volatility ahead.