Micron signals HBM total addressable market crossing $100 billion by 2027; Qualcomm forecasts $15 billion in data center chip sales by 2029, sparking $400 billion AI semiconductor rally

A late-session surge in semiconductor shares boosted market capitalization by more than $400 billion on June 24, driven by bullish guidance from Micron Technology and Qualcomm that revived momentum across the AI chip sector.

Micron shares climbed roughly 12% in after-hours trading following quarterly earnings that exceeded analyst expectations. The company's strong results underscored that substantial investments in AI infrastructure will drive demand for its memory chips. Separately, Qualcomm projected approximately $15 billion in revenue from its data center business by 2029 as it pivots from smartphones toward AI-based solutions.

The optimism spread across the semiconductor ecosystem. Western Digital, SanDisk, and Seagate Technology each gained more than 8%. Arm Holdings rose about 6%, Marvell added nearly 4%, and Broadcom climbed roughly 2%. Equipment suppliers benefited as well, with Applied Materials and ASML both gaining more than 4%.

The positive forecasts arrived amid investor concerns that AI valuations had become inflated. The PHLX Semiconductor Index had fallen 8% on Tuesday as markets questioned whether data-center spending would translate into near-term profits. Despite that early-week weakness, the index remained substantially elevated, up approximately 90% year-to-date. Micron alone had gained more than 260% in 2026 prior to Wednesday's rally.

Going forward, surging demand for memory and Qualcomm's expansion into AI segments position the chipmaker sector to sustain its momentum.