SK Hynix invests $720B in world's largest memory fab network

SK Hynix is pouring $720 billion into building what it calls the world's largest network of memory factories in South Korea, betting that explosive demand for artificial-intelligence chips will keep the high-bandwidth memory market red-hot. The company, whose market value has surged more than fivefold in the past year to top $1 trillion, is expanding at a scale that is reshaping the traditionally cyclical memory industry.

The buildout affects the entire AI supply chain. SK Hynix controlled 58% of the high-bandwidth memory, or HBM, market in the first quarter, with Samsung and Micron each holding 21%, according to Counterpoint Research. Big Tech companies are scrambling to lock in supply: SK Hynix reported in July that it signed 10 long-term agreements with major customers, and SK Group chairman Chey Tae-won said in an interview that "everybody wants to buy the memory chips" because without them, companies cannot produce AI computing and AI chips.

The investment matters because HBM is now a strategic bottleneck for AI processors. Made by stacking general-purpose DRAM, HBM consumes so much production capacity that it is depleting the supply of memory for consumer electronics. SK Hynix's Nasdaq listing in July raised $26.5 billion—the most ever by a foreign company on U.S. markets—to help fund the expansion. Since peaking at almost $195 on July 14, the U.S.-listed shares have fallen about 21% to close at $154.41 on Wednesday, amid broader volatility in chip stocks and a decline in the Korean market, which gets about half its value from SK Hynix and Samsung.

The expansion is part of a larger plan announced by South Korean President Lee Jae Myung in June to double the country's memory production in five years. SK Hynix's Yongin Cluster will include a fab as tall as a 50-story apartment building with six connected cleanrooms, a vertical design that contrasts with sprawling single-story fabs in Arizona from TSMC and Intel. The company is also building a $4 billion packaging facility in West Lafayette, Indiana, set to finish construction in 2028, and it operates the Solidigm subsidiary near Sacramento, California, after buying Intel's NAND business for $9 billion in 2020.

Competition is intensifying. Micron is spending $50 billion on two new memory fabs in Boise, Idaho, with the first scheduled to start making wafers in 2027, and is building a $100 billion campus with up to four fabs in Clay, New York. China's CXMT is emerging as a rival after a blockbuster debut on the Shanghai market, and Counterpoint Research director MS Hwang warned that "the counterparty of the race is China," calling it "a lot more dangerous than anything else in the world." SK Hynix is prohibited from selling leading-edge HBM in China due to U.S. export controls.

SK Hynix sees custom HBM as a way to insulate its massive investment from risk. Chey Tae-won said memory is at a "turning point" as next-generation HBM5 is co-designed with AI processors, with Nvidia and Google each wanting their own customized versions. "It actually changes the memory chip's status," he said.