US Stocks Open Higher as AI, Chip Shares Rally and Oil Tumbles 3% on US-Iran Talks

Major US equity indexes opened higher on Monday, September 21, 2026, led by a rebound in AI and semiconductor shares, while crude oil slumped more than 3% to an 11-day low on signs of progress in US-Iran negotiations, easing inflation concerns tied to energy prices. The Dow Jones Industrial Average rose 222.32 points, or 0.43%, to 51,904.96. The Nasdaq Composite gained 210.46 points, or 0.79%, to 26,733.00, and the S&P 500 added 42.53 points, or 0.56%, to 7,693.03, recovering all of September's losses. The Philadelphia Semiconductor Index climbed 1.60% to 12,112.01, with TSMC's US-listed shares up 0.83% at $437.84. Brent crude fell 3.27% to $100.47 a barrel, its fourth straight decline, as increased Middle East shipments through the Strait of Hormuz and potential US-Iran diplomacy cooled supply fears. The 10-year Treasury yield dropped to 4.963%, and Bitcoin touched $85,229.44, lifting crypto-linked stocks including Coinbase, up 5.11% at $204.17. Warner Bros. Discovery jumped 7.19% to $29.80 on reported settlement talks with California's attorney general over its Paramount merger. Accenture rose 6.58% to $193.21 after announcing a $1 billion AI partnership with Anthropic.