12:23 PM EDT, 04/28/2026 (MT Newswires) -- US equity indexes were mixed in Tuesday's midday trading, with the S&P 500 and the Nasdaq Composite sliding, as slumping semiconductor shares sent technology lower, and worsening Middle East geopolitics lifted crude oil futures.

The Nasdaq Composite dropped 1.3% to 24,568.2, and the S&P 500 slid 0.7% to 7,124.6. The Dow Jones Industrial Average, home mostly to old economy shares, climbed 0.2% to 49,259.3.

Microsoft ( MSFT )-backed (MSFT) OpenAI recently missed its own targets for new users and revenue, The Wall Street Journal reported late Monday, citing people familiar with the matter. Chief Financial Officer Sarah Friar expressed concern that OpenAI may not be able to pay for future computing contracts if sales fail to grow fast enough, the news report said, citing the people.

Among companies with a market capitalization of more than $200 billion, the worst performers were largely semiconductor names, including Arm Holdings ( ARM ) , Applied Materials ( AMAT ) , Lam Research (LRCX), Arista Networks (ANET), and Advanced Micro Devices (AMD), according to data compiled by Finviz.

Meanwhile, the United Arab Emirates will leave the Organization of the Petroleum Exporting Countries and its more expanded version, OPEC+, effective May 1, the Emirates News Agency reported.

This comes as Iran's latest proposal to end the war in the Middle East has still not won President Donald Trump's backing, leaving the deadly conflict in a continuing state of deadlock, Reuters said in a Tuesday report, citing an unnamed US official.

West Texas Intermediate crude oil futures jumped 3.6% to $99.80, and Brent crude futures advanced 2.6% to $111.08.