Micron announced a $250 billion investment program to expand HBM4 and HBM5 production capacity globally amid explosive AI memory demand.

Micron Technology announced this week it is raising its planned U.S. investment to more than $250 billion through 2035, a figure that would have been unthinkable for a memory chipmaker a decade ago. The expanded U.S. investment plan is the clearest sign yet that high bandwidth memory has become one of the most valuable commodities in the artificial intelligence buildout. It also reflects how AI has reordered the economics of an industry long defined by brutal boom-and-bust cycles.

Another signal of the memory boom came from Wall Street, where U.S.-listed shares of South Korean memory specialist SK Hynix made their debut, rising about 15% in midday trading. Micron marked its expansion announcement with the first concrete pour at its Clay, New York campus, arriving more than a quarter ahead of schedule and signaling that the company's spending plans are translating into physical construction, not just projections on a slide.

"As America celebrates its 250th anniversary, data and memory are foundational to the modern economy, and Micron is increasing our U.S. investments to more than $250 billion through 2035 to meet that moment," said Sanjay Mehrotra, Micron's chairman, president and CEO.

The scale of Micron's commitment tracks a broader repricing of memory driven by high bandwidth memory (HBM), the specialized chips that sit alongside GPUs in AI training and inference clusters. AI workloads consume far more DRAM (dynamic random-access memory) and HBM per server than conventional cloud computing, and that demand has turned what was once a commodity, cyclical business into one of the tightest bottlenecks in the AI supply chain.

Micron isn't the only beneficiary. Its chief HBM rivals, SK Hynix and Samsung Electronics, have both ridden the same wave, with all three companies now racing to lock in years of future capacity for AI customers.

SK Hynix, which holds the largest share of the global HBM market, listed its American depositary receipts (ADR) at $149 per share on the Nasdaq under ticker SKHY, raising $26.5 billion. At midday, shares traded at approximately $172. The company has said proceeds will fund expansion of its South Korean manufacturing facilities and purchases of extreme ultraviolet lithography equipment.