Micron and Qualcomm forecasts ignite $400 billion AI chip stock rally

The stock market experienced a substantial surge in chipmaker shares, collectively gaining over $400 billion in market value late Wednesday. This rally was ignited by robust forecasts from industry giants Micron Technology and Qualcomm, breathing new life into the recently faltering AI stock market.

Micron Technology's shares jumped 12% in extended trading after the company predicted quarterly earnings exceeding analysts' expectations. This positive outlook suggests that significant investments in AI-related infrastructure are driving robust demand for its memory chips. The company's performance is a key indicator of the broader semiconductor industry's health, particularly within the AI sector.

Adding to the positive momentum, Qualcomm announced it anticipates $15 billion in sales from its data center business by 2029. This projection highlights the company's strategic pivot, moving beyond its traditional strength in smartphone chips to focus more intently on the burgeoning AI market. This diversification signals a significant shift in Qualcomm's business strategy.

Competitors and related companies also saw notable gains. Western Digital, Sandisk, and Seagate Technology, all rivals to Micron in the storage solutions space, climbed more than 8%. Arm Holdings rallied approximately 6%, Marvell added nearly 4%, and Broadcom increased by 2%. Furthermore, Applied Materials and ASML, crucial suppliers of specialized manufacturing equipment to semiconductor firms, both rose more than 4%.

These strong forecasts arrive amid growing investor concerns on Wall Street about stretched valuations for AI-related companies after years of consistent gains. The PHLX chip index had previously tumbled 8% on Tuesday, reflecting anxieties that massive spending on AI data centers might not yield increased revenue and profits quickly enough. Despite this recent weakness, the PHLX chip index remains up an impressive 90% year-to-date in 2026. Micron alone has seen gains exceeding 260% year-to-date, even before Wednesday's late-day rally.