SK Hynix is expanding production and research capacity across South Korea and the United States to defend its position in high-bandwidth memory (HBM), even as Samsung Electronics rapidly narrows the market-share gap. CEO Kwak Noh-jung said AI-memory demand will remain strong as computing requirements increase, with new facilities supporting next-generation DRAM, HBM4E, LPDDR6 and DDR6. SK Hynix's HBM4 is already integrated into NVIDIA's Rubin AI accelerator. The company is developing a global AI research center in the United States, a wafer fab in Indiana and additional capacity at the Yongin semiconductor cluster and Cheongju M15X facility. Counterpoint Research data showed Samsung's HBM revenue share rising to 33% in the second quarter from 21% in the first, while SK Hynix's share fell to 50% from 58%. Improved Samsung HBM4 yields, in-house 4-nanometer base-die production and planned capacity increases are intensifying competition, although industry demand is still expected to exceed supply. Global HBM bit demand is forecast to grow 62% in 2026, compared with consensus supply growth of 50%, while HBM4 prices are projected to rise about 65% from this year. Micron and China's CXMT are also expanding, adding pressure to the three major suppliers. The AI-memory expansion has supported South Korean materials supplier Soulbrain, whose second-quarter operating profit rose 128.2% year over year to 46.021 billion won, but higher input costs and tougher memory competition could constrain future margins.