SK Hynix tops Samsung as Korea's most valuable company at $1.36 trillion

SK Hynix ended Samsung Electronics' 27-year reign as South Korea's most valuable company, a milestone powered by the AI memory chip boom.

SK Hynix's market capitalization hit 2,084.65 trillion won ($1.36 trillion) on Monday, surpassing Samsung Electronics by about 456 billion won, as the AI-driven demand for high-bandwidth memory chips reshuffled the pecking order in South Korea's semiconductor industry.

"The market cap reversal reflects SK Hynix's dominant position in the HBM market, where it has secured Nvidia as its marquee customer," Lee Jae-man, an analyst at Hana Securities, said. "But expectations have run ahead of actual earnings — this could signal the end of the current bull market."

SK Hynix shares surged 5.8 percent on the day, while Samsung gained just 0.7 percent. Over the past year, SK Hynix has soared 1,024 percent, more than double Samsung's 498 percent rise. The company's stock has climbed more than 340 percent in 2026 alone, compared with Samsung's roughly 200 percent gain. Samsung had held the top spot on the Korea Exchange since 2000, ending a streak of about 25 years and seven months.

The shift shows how the AI infrastructure buildout by U.S. tech giants has created a new semiconductor hierarchy. SK Hynix's early lead in HBM (high-bandwidth memory, a critical component for AI processors) has made it the primary memory supplier to Nvidia, while Samsung's broader portfolio spanning smartphones, home appliances and displays has diluted the AI tailwind on its overall valuation. SK Hynix is also pursuing a U.S. ADR listing, which analysts say could improve foreign investor access and potentially open the door to inclusion in global semiconductor indexes.

The HBM Advantage That Reshaped the Market

SK Hynix's ascent marks a dramatic reversal for a company that nearly collapsed under debt two decades ago. The turnaround has been fueled by its early bet on HBM technology, which stacks memory chips vertically to deliver the bandwidth required for AI training and inference workloads. Nvidia's H100 and Blackwell GPUs rely on SK Hynix's HBM3 and next-generation HBM4 memory, giving the Korean chipmaker a locked-in position in the AI supply chain.

The company's market value briefly topped $1 trillion for the first time in May, joining Samsung and Micron Technology in that milestone. But while Samsung and Micron have also benefited from the AI memory boom, SK Hynix's narrower focus on memory chips — and its head start in HBM — has amplified the impact on its stock price. Samsung's preferred shares, which carry a combined market cap of about 184 trillion won, still leave the overall Samsung entity larger when included.

A Warning From History

Not all analysts see the market cap flip as an unqualified positive. Lee at Hana Securities drew a parallel to the dot-com bubble of 2000, when Cisco Systems climbed to the top of global market cap rankings on inflated earnings expectations before collapsing. He argued that SK Hynix's valuation has run ahead of its actual earnings power, a pattern that historically has preceded market corrections.

The contest between the two companies will now hinge on HBM market share and AI semiconductor competitiveness going forward. SK Hynix trades at a premium reflecting its pure-play AI memory exposure, while Samsung's conglomerate structure means its chip division's success is partially obscured by its other businesses. For investors, the question is whether SK Hynix can sustain its technological lead as Samsung and Micron ramp their own HBM production.

This article is for informational purposes only and does not constitute investment advice.