Nasdaq Hits Record High: Semiconductor Stocks Lead AI Rally in September 2026

The Nasdaq Composite reached a new all-time high on September 21, 2026, with 27,122.09 points, gaining 599.55 points or 2.26 percent. It was the first record close since June 2, 2026. Semiconductor stocks led a broad market rally that extended across all major US indices.

The S&P 500 rose 114.20 points or 1.49 percent to 7,764.70 and closed around 0.4 percent below its record high from August 13. The Dow Jones Industrial Average gained 366.19 points or 0.71 percent to 52,048.83 points.

AMD Breaks Trillion-Dollar Mark – Chip Stocks Post Double-Digit Gains

Advanced Micro Devices recorded a price increase of around 10 percent on September 21 and exceeded a market capitalization of 1 trillion US dollars for the first time. AMD became the fourth US chipmaker to reach this threshold – after Nvidia, Broadcom, and Micron.

Other semiconductor stocks posted significant gains on September 21:

• Intel: Plus 12.2 percent
• Arm Holdings: Plus 17 percent
• Qualcomm: Plus over 9 percent

The PHLX Semiconductor Index – an industry barometer – jumped 4.3 percent. The iShares Semiconductor ETF (SOXX) closed nearly 5 percent higher.

Tech Heavyweights Benefit from Easing AI Concerns

The rally also swept up other major technology stocks. Meta posted a price jump of 11.4 percent on September 21 after Wells Fargo raised its price target following the company's launch of the AI assistant Muse. Nvidia gained 2.30 percent, TSMC won 2.41 percent, Broadcom 1.60 percent, and Micron 2.77 percent.

Tesla rose 3.03 percent, Microsoft 1.61 percent, Amazon 1.87 percent, Apple 0.85 percent, and Alphabet 1.55 percent. SK Hynix declined 0.73 percent, SpaceX dropped 0.56 percent.

According to sources, investors reacted to signs that AI spending continues to expand, even though AI industry leaders had issued security warnings about a week earlier – around September 14 – that triggered a global tech selloff. The market reversal reflects easing concerns about a slowdown in AI investments.

Oil and Bond Yields Support Sentiment

The rally was supported by movements in oil and bond markets, which market strategists characterized as a shift "from headwinds to tailwinds." The yield on ten-year US Treasury securities fell below the psychologically important 5 percent mark and dropped during the September 21 session to as low as 4.943 percent before closing around 4.95 percent – more than 0.04 percentage points lower than the previous day. This marked a retreat from levels above 5 percent that had been reached following the Federal Reserve's rate hike.

Oil prices fell sharply: Brent Crude declined 3.4 percent to 100.34 US dollars per barrel – the lowest close since September 8 and the largest single-day loss since August 25. US West Texas Intermediate (WTI) fell 4.5 percent to 95.78 US dollars.

The oil price decline was attributed to speculation about a possible breakthrough in Middle East negotiations at a UN General Assembly meeting. President Donald Trump signaled openness to a meeting with Iranian President Masoud Pezeshkian, who was scheduled to attend the UN General Assembly in New York that week. Trump was scheduled as a speaker for September 22, Pezeshkian for September 23.

Fed Policy and Valuations in Focus

The Federal Reserve had raised rates for the first time in three years in the week before September 21 to combat inflation. According to CME FedWatch data, traders showed a 50 percent probability of another rate hike the following month on September 21. Comments from at least ten central bank officials were scheduled for that week.

According to LSEG data, the S&P 500 was valued at just under 19 times expected earnings on Friday, September 20 – the lowest valuation since 2023. AI-related heavyweights contributed much of the recent rise in earnings expectations, according to sources.

Hyperscalers Drive Semiconductor Demand

On September 16, sources reported that hyperscalers – large cloud providers – preferred orders for custom chips, high-bandwidth memory, and network chips. Semiconductor companies subsequently raised their forecasts. One company saw a revenue trajectory of 230 billion US dollars, another was expected to report before month-end.

At the end of August, Micron Technology was described as the semiconductor stock with the "most explosive chart:" The stock was up 227.94 percent year-to-date and 695.68 percent year-over-year at 935.39 US dollars at that time. Micron's fourth quarter fiscal results were scheduled for September 30.

Greenland Stocks Rise After Diplomatic Progress

Outside the tech sector, US-listed stocks of companies with Greenland ties rose on September 21 after progress in diplomatic negotiations between the US and Denmark over Greenland's status became known. Greenland Mines tripled in value, Greenland Energy more than doubled.