SK Hynix has displaced Samsung Electronics as South Korea's most valuable listed company, ending a run at the top of the Korea Composite Stock Price Index that Samsung had held without interruption since November 2000. SK Hynix's market capitalisation reached roughly 2,082.5 trillion won, about $1.35 trillion, edging past Samsung's 2,081.3 trillion won in a shift that traders and analysts have been anticipating for months as the two companies' fortunes in the memory-chip business diverged sharply.
The reversal traces directly to the artificial intelligence boom reshaping global chipmaking. SK Hynix has become the dominant supplier of high-bandwidth memory, or HBM, the specialised chips that sit alongside processors in AI servers built for customers including Nvidia and Google parent Alphabet. Estimates of SK Hynix's share of the global HBM market vary by source and quarter, but most put the company comfortably ahead of both Samsung and Micron, with SK Hynix shares having rallied more than 340 percent over the past year as investors piled into the AI memory trade.
The scale of the turnaround is notable given SK Hynix's history. The company, originally Hynix Semiconductor, came close to being sold off to Micron in 2002 after years of crushing debt left it under the control of its creditors for roughly a decade. Its emergence as the country's most valuable company marks one of the more dramatic corporate comebacks in South Korean industry, built on a bet that memory chips optimised for AI workloads would become as strategically important as the processors themselves.
The shift also carries weight beyond the two companies involved. Samsung remains far larger as a conglomerate and continues to compete aggressively on next-generation HBM technology, recently shipping its own advanced samples to customers in a bid to close the gap. But for a stock market where Samsung's dominance had long been treated as a fixture, SK Hynix's rise underscores how completely the AI infrastructure race has rewritten the pecking order among the world's memory chipmakers, with ripple effects already being watched closely ahead of upcoming earnings from rival Micron.
