Nasdaq hits record high on AI and semiconductor momentum

The Nasdaq Composite reached a new record high on September 22, 2026, marking its fourth consecutive positive session. The index closed at 27,231.59, driven primarily by momentum in the technology sector, specifically regarding artificial intelligence infrastructure spending, semiconductor demand, and cloud computing growth.

While the Nasdaq saw significant gains, broader market performance was mixed. The Dow Jones Industrial Average declined by 0.4%, and the S&P 500 finished nearly flat, trailing its own record peak by 0.7%. Notable gainers included Monolithic Power Systems, which rose 8%, alongside Western Digital and Sandisk, reflecting strong demand for data storage solutions.

Market analysts noted that while tech-led gains are robust, market breadth is narrowing as a small number of mega-cap companies drive most returns. Investors are closely monitoring the next stage of the AI investment cycle, looking for actual orders and operating results to confirm that infrastructure spending is translating into durable revenue.