S&P 500 fell 0.4% to 6,586.6, Nasdaq slipped 0.6% to 21,879.3, and Dow dropped 0.3% to 46,539.5 on Tuesday.
President Trump gave Iran until 20:00 ET Tuesday to reopen the Strait of Hormuz, threatening attacks on bridges and power plants.
Brent crude rose 0.6% to $110.41 per barrel and WTI climbed 3.1% to $115.84, pushing energy prices higher.
Broadcom jumped >3% after an AI partnership with Google; Humana and UnitedHealth surged about 10% and 9% on higher Medicare rates.