SK Hynix overtook Samsung Electronics on June 22, 2026, to become South Korea's most valuable publicly traded company for the first time since 2000, driven by its dominant 61% share of the global high-bandwidth memory market. The shift reflects how the AI infrastructure boom is redrawing the semiconductor hierarchy, rewarding specialized HBM expertise over scale in conventional DRAM. Samsung, struggling with HBM qualification issues at Nvidia, now holds just 17% of a segment that defines the AI