What China’s HBM catch-up should teach Korea

Two headlines in June should shape Korea’s artificial intelligence (AI) debate. The first was a victory lap. SK hynix overtook Samsung Electronics by common-share market capitalization for a day, powered by high-bandwidth memory (HBM) chips used in AI systems. Samsung has a fair caveat: If preferred shares are included, it remains larger. But the market signal was clear. AI has turned memory from a cyclical commodity into critical infrastructure. The second headline was less comfortable. Korean and industry reports suggest China’s ChangXin Memory Technologies (CXMT) is moving faster in HBM than many in Seoul expected. Korea still leads. But the margin is narrowing, and that should change how Seoul thinks about its AI goals. Start with what the CXMT story actually shows. HBM3 is no longer the frontier. Nvidia’s Rubin platform uses HBM4, and Korean firms are already pushing into HBM4 and HBM4E. SK hynix has shipped samples of 12-layer HBM4E chips to major customers, while Samsung has showcased HBM4 and HBM4E products for Nvidia’s next-generation platforms. CXMT is trying to close