(Updates with index/price moves and company/geopolitical news from the first paragraph.)

US equity indexes traded mixed as mega-cap semiconductor names pushed technology to the bottom of sector charts.

The Nasdaq Composite fell 0.4% to 26,083.7, and the S&P 500 declined 0.2% to 7,662.4 after midday Monday. The Dow Jones Industrial Average bucked the intraday trend, rising 0.2% to 53,394.9.

Among companies with market capitalizations exceeding $200 billion each, nine of the bottom 10 names by intraday returns were in the technology sector, according to data compiled by Finviz. Of those nine firms, eight were related to the semiconductor industry. Sandisk (SNDK) led the pack of tech decliners, down 8.6%.

US Treasury yields traded mixed, with the 30-year down 5.9basis points to 5.22%, the 10-year lower by 4.6 basis points to 4.69% and the two-year little changed at 4.24%. The US Treasury Department may tap its General Account to help fund its buyback operation, CNBC reported.

The US is set to warn countries to cut ties with Iran or risk their businesses being cut off from the dollar-based financial system when it unveils the "greatest financial offensive ever" on Monday, a source told Reuters.

Treasury Secretary Scott Bessent will outline measures at 1 p.m. to broaden the scope of potential secondary sanctions on entities and countries that maintain economic ties with Iran, the source, who was familiar with the plans but not authorized to speak publicly, told the news agency.

The front-month US West Texas Intermediate crude oil contract retreated 2.3% to $85.03 per barrel, and global benchmark North Sea Brent slumped 2% to $92.47 per barrel.

Nvidia (NVDA) customers are facing price increases of over 15% on servers equipped with its artificial intelligence chips due to rising memory costs, Bloomberg reported Saturday, citing people familiar with the matter. Separately, Nvidia is discussing an investment in AI startup Perplexity as part of a funding round that would value the company at more than $30 billion, The Information reported Sunday, citing people familiar with the talks.

Shares of Nvidia declined 2.1%, among the Dow's worst performers.