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

Chip stocks surged late Wednesday, adding over $400 billion in market value after strong forecasts from Micron Technology and Qualcomm reignited the AI rally. Micron jumped 12% in extended trading, forecasting quarterly earnings above estimates and signaling robust demand for memory chips driven by AI infrastructure investments. Qualcomm projected $15 billion in data center sales by 2029 as it shifts focus from smartphones to AI.

Rivals Western Digital, Sandisk and Seagate each gained more than 8%. Arm Holdings rallied about 6%, Marvell added nearly 4%, and Broadcom climbed 2%. Equipment makers Applied Materials and ASML rose over 4%.

The rally follows recent worries that AI stock valuations had become stretched. The PHLX chip index fell 8% on Tuesday amid concerns that massive data center spending may take too long to pay off. Despite the dip, the index is up 90% year to date in 2026, and Micron has gained over 260% in the same period.