NEW YORK, UNITED STATES — US stocks rallied on September 21, with the Nasdaq climbing 2.3% as semiconductor shares advanced and falling oil prices and Treasury yields eased pressure on Wall Street.
US stocks surged on Monday as technology shares rebounded, crude oil prices declined and Treasury yields eased, giving investors relief from some of the pressures that had unsettled financial markets during the previous week.
The Nasdaq Composite led the major indexes, climbing 2.3% to a record closing level of 27,122.09. The S&P 500 gained 1.5% to finish at 7,764.70, while the Dow Jones Industrial Average advanced 0.7% to 52,048.83, according to closing figures published by the Associated Press.
The advance was supported by gains in semiconductor companies and other businesses associated with artificial intelligence. Lower energy prices and bond yields also improved the financial backdrop, helping lift shares beyond the technology sector.
The rally carried the S&P 500 to within approximately 0.4% of its all-time high, while the Nasdaq established a new closing record. Nevertheless, oil remained substantially more expensive than earlier in the summer, and the yield on the benchmark 10-year US Treasury note remained elevated.
Nasdaq reaches record close as major indexes advance
Monday's performance represented a broad rebound in US equities, although the largest gains were concentrated in technology and communication services.
The Nasdaq gained 599.55 points, reflecting renewed demand for companies connected to artificial intelligence, including chip designers and manufacturers.
The S&P 500 rose 114.20 points, while the Dow added 366.19 points. Smaller companies participated in the advance, with the Russell 2000 rising 14.96 points, or approximately 0.5%, to 2,875.36.
US stock market: September 21 closing figures
Index | Closing level | Daily change |
|---|---|---|
Nasdaq Composite | 27,122.09 | +2.3% |
S&P 500 | 7,764.70 | +1.5% |
Dow Jones | 52,048.83 | +0.7% |
Russell 2000 | 2,875.36 | +0.5% |
The S&P 500's performance was particularly significant because the index had been approaching its previous record after a period of market uncertainty.
Its closing level left it just below the historic high established in August. The Nasdaq, meanwhile, surpassed its previous closing record from June, according to market coverage published on Monday.
The distinction matters because the indexes represent different parts of the US equity market. The Nasdaq has substantial exposure to technology-oriented businesses, whereas the Dow follows 30 large, established companies and the S&P 500 covers a broader range of major US corporations.
A technology-led rally can therefore produce different percentage gains across the benchmarks even when all three move in the same direction.
AMD, Intel and Meta help drive the technology rebound
Artificial intelligence-related companies were among the principal contributors to Monday's gains.
Advanced Micro Devices rose approximately 10%, taking its market capitalization beyond $1 trillion. Intel gained about 12%, while the PHLX semiconductor index advanced 4.3%, according to Reuters and the Financial Times.
The gains reflected renewed interest in businesses supplying computing power for AI applications, including advanced processors and related semiconductor technology.
Meta Platforms also contributed to the rally. Its shares climbed 11.4% as investors responded to developments surrounding the company's Muse AI assistant and a favorable analyst reassessment.
These movements illustrate the extent to which expectations for AI investment continue to influence major US stock indexes.
Demand for advanced computing infrastructure has become an important consideration in valuations across semiconductor manufacturing, cloud computing and digital services.
However, the relationship between AI investment and future profitability remains subject to uncertainty. Companies may experience substantial share-price movements as investors reassess anticipated spending, competition and earnings.
Monday's gains showed renewed investor interest in the sector, but they do not establish how individual companies or the broader market will perform in subsequent sessions.
Falling Brent crude prices ease inflation concerns
Energy markets provided another important source of support.
Brent crude fell 3.4% to approximately $100.34 per barrel, according to Associated Press reporting. That represented a retreat from nearly $110 during the preceding week, although prices remained well above the roughly $72 level seen earlier in the summer.
The decline followed speculation about possible diplomatic progress involving the United States and Iran around the United Nations General Assembly.
Reuters reported that expectations of talks contributed to the retreat in oil prices. The possibility of improved diplomatic conditions influenced sentiment, although the outcome of any negotiations remained uncertain.
Oil prices are particularly important for financial markets because energy affects transportation, manufacturing, electricity generation and household spending.
When crude prices rise sharply, businesses can face higher operating costs, while consumers may have less disposable income after paying for fuel and other necessities.
Persistent energy inflation can also complicate the outlook for monetary policy.
Conversely, a decline in oil prices can reduce some of those pressures. That does not mean a single day's movement immediately changes consumer inflation, but it can influence expectations about future costs.
Monday's retreat therefore helped explain why investors responded positively even as oil remained expensive by recent historical standards.
Treasury yields decline as financial conditions improve
Bond markets reinforced the improvement in sentiment.
The yield on the benchmark 10-year US Treasury note fell to approximately 4.95%, according to the Associated Press. Reuters also reported that the yield had moved below 5%.
The 10-year Treasury yield is a widely followed reference point for borrowing costs and asset valuations.
When yields rise, government bonds can become more attractive relative to equities. Higher yields can also increase financing costs for companies and affect the present value investors assign to expected future earnings.
That valuation effect can be particularly relevant for growth-oriented companies whose market prices depend heavily on expectations of earnings many years ahead.
Declining yields can ease those pressures, although the effect varies across companies and sectors.
Monday's combination of lower yields and stronger technology shares was therefore consistent with an improvement in the market's valuation environment.
The relationship is not automatic. Falling yields can sometimes reflect concerns about economic growth rather than an improvement in investor confidence.
In this session, however, the simultaneous advance in major stock indexes suggested that investors were responding positively to the combination of lower energy prices, reduced bond-market pressure and renewed enthusiasm for AI-related companies.
Global stock markets join the Wall Street advance
The recovery extended beyond US exchanges.
The Associated Press reported gains exceeding 1% in markets including Germany, Hong Kong and South Korea, reflecting a broader improvement in international equity sentiment.
This international response matters because energy prices, US bond yields and the performance of large technology companies influence investment decisions across multiple markets.
Lower oil prices can affect the outlook for energy-importing economies, while movements in US Treasury yields can influence international borrowing costs and capital flows.
Technology supply chains also cross national boundaries. Companies involved in semiconductor production, electronic components and computing infrastructure operate across the United States, Europe and Asia.
Nevertheless, the economic implications of lower oil prices differ between countries. Importers may benefit from reduced energy costs, while producers can experience lower export revenue.
A global equity rally should therefore not be interpreted as evidence that every economy or industry benefits equally.
S&P 500 extends its annual gain as investors assess risks
Monday's advance added to substantial gains already recorded by major US benchmarks during 2026.
According to the Associated Press, the S&P 500 was up 13.4% for the year following Monday's close. The Nasdaq had gained 16.7%, the Dow 8.2% and the Russell 2000 approximately 15.9%.
The figures indicate that the rally occurred within a market that had already delivered positive year-to-date returns, despite recent fluctuations.
The different performances also illustrate how market leadership has varied across company sizes and sectors.
Technology's contribution to the Nasdaq's advance has been especially important, while the Russell 2000 provides a separate perspective on smaller publicly traded US companies.
Investors will continue to assess whether lower energy prices and Treasury yields can be sustained, alongside developments in corporate earnings and AI investment.
Oil remains sensitive to geopolitical developments, while bond yields can change in response to inflation data, monetary policy expectations and economic conditions.
Monday's closing figures establish that US equities experienced a strong session, with technology shares leading and the broader market participating. Whether those conditions persist will depend on developments beyond a single trading day.