SK Hynix overtakes Samsung as Korea’s most valuable company

For a quarter of a century, the most valuable company in South Korea was Samsung Electronics, and the question was never really open. On Wednesday it became open, and then it closed the other way.

SK Hynix, the smaller of the country’s two memory-chip makers, passed Samsung in market capitalisation during intraday trading, taking the top spot on the Korea Exchange for the first time since Samsung claimed it in November 2000.

By midday, SK Hynix’s common shares were worth roughly 2,057 trillion won, narrowly ahead of Samsung’s 2,051 trillion. The gap is slim enough to carry a caveat: include Samsung’s preferred shares, worth around 180 trillion won, and the older company is still comfortably larger overall.

On common stock alone, though, the bellwether has changed, and SK Hynix shares rose more than 5 per cent on the day, pulling the wider KOSPI up with them.

The cause is not in dispute. SK Hynix has spent two years as the dominant supplier of high-bandwidth memory, the stacked chips that sit beside Nvidia’s accelerators and feed them data fast enough to keep up.

Nvidia controls the overwhelming share of the AI training market, and SK Hynix has been its principal HBM partner, commanding the majority of the segment’s revenue in recent quarters. That position turned a perennial number two into the company the market now prizes most.

Samsung, by contrast, has spent the cycle playing catch-up in exactly the product that matters. It has been qualifying its own HBM for Nvidia and is expected to win a larger slice of next-generation HBM4 orders, but for the moment it has watched a rival it once dwarfed close the distance and then cross it. In January, SK Hynix had already overtaken Samsung in annual profit for the first time. The market value was the part that had not yet caught up.

There is a second reason buried in the share price. SK Hynix has been preparing a US listing of American depositary receipts, a move analysts have linked to its recent run, and which would give international investors a cleaner way to own the company without trading in Seoul. The chipmaker has not put a firm date on it.

What the milestone marks, more than anything, is how completely the AI build-out has reordered the Korean market. SK Hynix and Samsung between them now account for roughly half of the KOSPI’s entire value, a concentration that cuts both ways: it lifted the index to records on Wednesday, and it means a single soft quarter in memory demand can take the whole market down with it. If SK Hynix keeps the crown is, in the end, a question about how long the appetite for AI memory holds.