SK Hynix Ends Samsung's 25-Year Run as South Korea's Most Valuable Company on June 22

Since SK Hynix surpassed Samsung in annual profit for the first time in January 2026, Monday's market cap crossing was the final step in a reversal that had been building for years, not a sudden upset.

On June 22, SK Hynix closed at 2,919,000 won per share, up 5.61% on the day, according to data from the Korea Exchange reported by The Elec. That pushed its common-share market capitalization to 2,080.38 trillion won, clearing Samsung Electronics' 2,066.66 trillion won on the same measure. The last time any company held the top KOSPI spot was November 21, 2000, when Samsung first claimed it.

Monday's close was the eighth consecutive winning session for SK Hynix, according to AI Weekly, which cited Nikkei Asia and KED Global. Shares rose on the same investor thesis that has been compressing Samsung's relative valuation for months: SK Hynix is the dominant supplier of high-bandwidth memory chips for AI accelerators, particularly Nvidia's GPU stacks.

What's Actually Driving This

SK Hynix has spent roughly two years as the primary HBM supplier for Nvidia's accelerators, commanding the majority of segment revenue across recent quarters, as The Next Web noted in reporting cited by AI Weekly. That position paid off visibly in Q1 2026: SK Hynix posted an operating profit of 37.61 trillion won ($25.4 billion) at a 72% operating margin, per KED Global. The company has also stated that demand for its next-generation HBM4 chips is projected to exceed its own production capacity for the next three years.

Samsung's situation is structurally different. Its semiconductor division benefits from rising memory prices, but those same price increases raise input costs for its consumer electronics businesses, including smartphones, televisions, and home appliances. Weak results in its non-memory units, specifically foundry and System LSI operations, have limited its share-price gains relative to SK Hynix, according to The Elec. A focused pure-play chips business outpaced a conglomerate during an AI hardware supercycle.

The Asterisk

The common-share comparison, while standard for KOSPI rankings, isn't the full picture. Samsung Electronics' preferred shares carried a value of approximately 180 trillion won as of June 22, according to both The Elec and AI Weekly. Add those in and Samsung remains the larger company by total market capitalization. The KOSPI ranking uses common shares, so SK Hynix holds the official top position under that methodology, but no one should claim Samsung has been overtaken on every measure.

AI Weekly also flags a gap in the milestone coverage. It's not entirely clear from the available reporting whether SK Hynix held the top spot only intraday or at market close, and The Elec's close-price data suggests it did close above Samsung on common shares. The discrepancy matters because intraday crossings have happened before without sticking.

The Skeptic's Case

A 72% operating margin is exceptional by any historical standard, and critics of the current SK Hynix valuation make a reasonable point: that margin depends on two conditions holding simultaneously, sustained AI hardware investment at its current pace, and Nvidia continuing to source HBM primarily from a single partner. Neither condition is guaranteed. AI infrastructure spending has already attracted scrutiny over whether the buildout is outrunning actual monetization. And Samsung, despite its current HBM lag, has the engineering talent and capital to close technology gaps over time. Investors pricing SK Hynix at a premium to Samsung are betting that the AI hardware cycle remains both intense and prolonged, and that Samsung's foundry and HBM recovery stays slow. Those are real bets, not certainties.

The US Listing Angle

SK Hynix's valuation trajectory also has a structural catalyst on the horizon. In March 2026, the company confidentially submitted registration documents to the U.S. Securities and Exchange Commission for a potential American Depositary Receipt listing, according to The Elec. Market participants believe a U.S. listing could expand global investor access and push SK Hynix's valuation multiples closer to those of major U.S. semiconductor companies, which have historically traded at higher earnings multiples than Korean-listed peers.

No timeline for that listing has been made public. The SEC submission is confidential, meaning the full terms and pricing structure aren't yet known. Whether an ADR materializes, and when, remains the clearest near-term variable for where SK Hynix's market cap goes from here.