# SK Hynix South Korean memory chip manufacturer that has emerged as the most critical supplier in the AI infrastructure stack after [[NVIDIA]] itself. SK Hynix dominates the market for HBM (high-bandwidth memory) — the specialized stacked DRAM chips that sit beside NVIDIA GPUs and feed them data at terabyte-per-second speeds. The company holds an estimated 60–70% of HBM4 volume allocated to NVIDIA's Vera Rubin platform, making it the de facto monopoly supplier of the memory that makes AI training possible. In June 2026, SK Hynix and [[NVIDIA]] announced a multi-year technology partnership covering co-development of next-generation memory across NVIDIA's Vera Rubin supercomputers, Vera CPUs, RTX Spark PCs, and Jetson Thor robotics platforms — extending the relationship beyond simple supply into joint R&D. The partnership also includes AI-driven chip design and autonomous fab manufacturing, blurring the line between customer and co-developer. Only three companies manufacture HBM at scale: SK Hynix, [[Samsung]], and [[Micron]]. SK Hynix's dominance in this triopoly means it occupies a chokepoint position in the AI supply chain comparable to [[ASML]]'s monopoly in lithography or [[TSMC]]'s dominance in advanced logic fabrication. Its entire 2026 HBM production is sold out. The company is a subsidiary of SK Group, one of South Korea's largest chaebols. ## See Also - [[NVIDIA]] — its primary customer and R&D partner - [[Samsung]] — its Korean memory rival - [[Micron]] — the third HBM manufacturer (and only US-based one) - [[TSMC]] — fabricates the logic chips SK Hynix memory serves - [[Chip Export Controls]] — the geopolitical context for memory manufacturing