12:39 PM EDT, 07/27/2026 (MT Newswires) -- (Updates with index/price moves and company/geopolitical news from the first paragraph.)

US equity indexes traded mixed amid growing investor concerns over circular corporate investments and as crude oil prices plunged after a pause in Iran strikes entered its third day.

The Dow Jones Industrial Average climbed 0.6% to 52,249.1, and the S&P 500 rose 0.1% to 7,420.2 after midday Monday. The Nasdaq Composite was little changed at 24,972.6.

Energy and technology led decliners while communication services, consumer staples, and consumer discretionary topped the gainers.

Nvidia ( NVDA ) has agreed to expand its partnership with South Korean conglomerate SK Group through an artificial intelligence infrastructure initiative valued at more than $500 billion. The deal announced Saturday includes a long-term partnership between Nvidia ( NVDA ) and SK Hynix ( SKHY ) that will provide the US technology giant a stable supply of next-generation AI memory. Nvidia's ( NVDA ) shares dropped 4.5%, one of the bottom five in the Dow. The SK Hynix ( SKHY ) stock plummeted 8%.

VanEck Semiconductor ETF ( SMH ) , with net assets of $77.2 billion, slumped 4.4%.

Meanwhile, the US paused military attacks against Iran over the weekend, while Tehran also refrained from retaliatory action, according to a Commerzbank note. Meanwhile, Oman and Iran continued discussions on a transit arrangement for the Strait of Hormuz, with diplomats describing the negotiations as "moving in the right direction." Iranian officials likewise characterized the talks as "constructive."

The front-month US West Texas Intermediate sank 6.3% to $83.65 a barrel, and global benchmark North Sea Brent plunged 6.9% to $90.09 a barrel.