Nasdaq notches record-high close, AI optimism reignites and Treasury yields retreat

Sept 21 (Reuters) – The Nasdaq surged to a record-high close on Monday, lifted by gains in Advanced Micro Devices and other AI heavyweights, while Treasury yields retreated from recent highs and crude prices tumbled to an 11-day low on speculation about a potential breakthrough in Middle East talks at a UN meeting this week.

Read more Powerball jumps to $313 million. Monday, Sept. 21, results, numbers

Chip stocks rallied, with Intel surging 12.2% and Arm Holdings up 17%. The PHLX semiconductor index jumped 4.3%.

Advanced Micro Devices rose about 10% to reach a market capitalization of $1 trillion for the first time.

The Nasdaq notched its first record-high close since June 2, while the S&P 500 ended about 0.4% below its August 13 record-high close.

Investors pointed to signs that suggest spending on AI is still expanding, despite recent safety warnings from leaders of AI giants a week ago that triggered a global tech selloff.

The benchmark US 10-year yield fell below the psychologically important 5% level as Brent crude futures dipped below $100 a barrel to their lowest level since September 9, later settling at $100.34 per barrel.

While Washington and Tehran exchanged threats through the weekend, US President Donald Trump said he would be open to meeting Iranian President Masoud Pezeshkian, who is expected to attend the UN General Assembly in New York this week.

“We’ve been kind of programmed to follow the price of oil and the yield on the US 10-year, and if you look at those two things today, they’ve shifted from being headwinds to tailwinds for this market, at least in the near term,” said ​Art Hogan, chief market strategist at B. Riley Wealth.

Meta shares soared 11.4% after Wells Fargo hiked its price target on the social media platform following the recent launch of its Muse AI assistant.

The S&P 500 climbed 1.49% to end the session at 7,764.70 points.

The Nasdaq gained 2.26% to 27,122.09 points, while the Dow Jones Industrial Average rose 0.71% to 52,048.83 points.

The S&P 500 last Friday traded at just under 19 times expected earnings, its lowest valuation since 2023, according to LSEG data. AI-related heavyweights are responsible for much of the recent increase in earnings expectations.

Read more Trading Day: AI euphoria back with a bang

Investors remained wary of the interest-rate outlook after the US Federal Reserve last week raised rates for the first time in three years to fight inflation. Traders see a 50% chance of another hike next month, CME’s FedWatch showed.

Commentary from at least 10 central bank policymakers is due this week.

US-listed shares of companies exposed to Greenland rose following progress in diplomatic negotiations between the United States and Denmark about the status of Greenland.

Greenland Mines tripled in value, while Greenland Energy more than doubled.

A Chinese-US summit on Thursday could cover topics including potentially extending the trade truce between the two superpowers, the Iran war and regulation of AI. A report said the US proposed to extend the trade truce by six months, while China sought a longer extension.

Bitcoin, a key marker of risk tolerance, rose over 6% to a more than seven-month high, lifting Coinbase and Strategy.

Paramount Skydance fell almost 3% after a source told Reuters the company had reached a settlement with California and 11 other states suing to block its $110 billion merger with Warner Bros Discovery.

Eight of the 11 S&P 500 sector indexes rose, led by communication services, up 4.16%, followed by a 2.4% gain in information technology.

Advancing issues outnumbered falling ones within the S&P 500 by a 1.4-to-one ratio.

The S&P 500 posted seven new highs and 29 new lows; the Nasdaq recorded 64 new highs and 127 new lows.

Volume on US exchanges was relatively strong, with 16.5 billion shares traded, compared with an average of 16.2 billion shares over the previous 20 sessions.

(Reporing by Johann M Cherian and Tharuniyaa Lakshmi in Bengaluru and Noel Randewich in San Francisco; Editing by Pooja Desai and Matthew Lewis)

Read more Hawks C Henri Veesaar tears ACL in workout, to miss ‘26-27

Copyright Reuters or USA Today via Reuters Connect

This story was originally published September 21, 2026 at 5:41 AM.