Seoul stocks slide nearly 1% as Nvidia uncertainty wipes out early gains

Seoul's benchmark KOSPI closed down 0.98 percent at 5,290.53 on Friday, erasing an early rally of more than 2 percent as investors turned cautious about what Nvidia CEO Jensen Huang's departure means for the artificial intelligence ecosystem. The reversal came fast. The index opened 2.05 percent higher, climbed as far as 5,504.44, and flipped into negative territory around 12:35 p.m. — all in a single session.

That swing is the story. A market that started the day buying risk ended it shedding chipmakers and internet stocks, because the single biggest question hanging over the AI trade right now is who steers Nvidia without Huang. He played a crucial role in the recent AI boom, and Wall Street's major indices closed lower overnight following news of his exit, setting the tone for trading in Asia.

Why did the KOSPI reverse course?

The mechanics are visible in the order flow. Foreign investors sold a net 550.5 billion won worth of Korean stocks. Institutions bought a net 2.3 billion won, and individuals purchased a net 17.2 billion won — nowhere near enough to absorb the foreign selling.

"KOSPI started higher but turned negative due to foreign sell-offs," said Lee Kyoung-min, an analyst at Daishin Securities. "Without prominent negative factors, rising AI uncertainties weighed heavily on the market."

That last point matters. There was no fresh Korean bad news — no earnings miss, no policy shock, no local crisis. The selling was about uncertainty itself, and uncertainty is enough when a market's biggest names are chained to the AI supply chain.

The numbers behind the session:

• Close: KOSPI down 52.20 points, or 0.98 percent, at 5,290.53
• Intraday range: opened 2.05 percent higher, peaked at 5,504.44, turned negative around 12:35 p.m.
• Volume: 237.3 million shares worth 16 trillion won ($11.9 billion), described as light
• Breadth: 450 advancing shares versus 418 declining shares

It wasn't a broad rout. More stocks rose than fell. The damage was concentrated exactly where you'd expect it — in technology.

Investors had a second thing on their minds, too. They were awaiting U.S. producer price data, which could offer a clue to the Federal Reserve's monetary policy path. That follows a steeper-than-expected rise in the consumer price index earlier in the week. So the session carried a double dose of caution: an AI leadership shock abroad and inflation uncertainty from the same country.

Which stocks took the hit?

Technology shares led the losses, and the declines ran from chips to internet platforms.

• SK hynix sank 3.03 percent to 1.2 million won
• Samsung Electronics, the market bellwether, lost 0.96 percent to 206,000 won
• Samsung Electro-Mechanics, Samsung's electronic component affiliate, tumbled 3.5 percent to 855,000 won
• Naver, the internet giant in which Nvidia is the third-largest shareholder, slumped 5.12 percent to 172,500 won

Naver's drop deserves a closer look, because it shows the mechanism at work. Nvidia isn't just a customer or supplier to the Korean market — it is a direct shareholder in one of its largest internet companies. When Nvidia's leadership situation turns uncertain, that exposure transmits the shock straight into Seoul-listed shares, not just through sentiment but through an actual ownership link.

SK hynix tells a similar story from the hardware side. The memory chipmaker is a key supplier inside the AI compute buildout, and a 3 percent single-day decline on no company-specific news shows how tightly the market prices Korean semiconductors as an AI proxy.

The selling wasn't confined to tech. State-run Korea Electric Power Corp. plunged 9.79 percent to 27,650 won — the sharpest drop among the names detailed in the session. Nongshim, a leading instant noodle maker, lost 4.43 percent to 366,500 won.

What actually rose?

The winners are the tell. Money didn't leave the Korean market on Friday; it rotated.

Hyundai Motor, the country's top carmaker, rose 1.13 percent to 269,500 won. KB Financial Group, a major banking group, jumped 4.74 percent to 159,000 won. Cars and banks — sectors whose earnings don't hinge on AI chip demand — absorbed the money flowing out of semiconductors and platforms.

That pattern is textbook risk rotation. When the AI thesis wobbles, investors don't necessarily head for the exits. They move to businesses valued on loans and vehicle sales rather than on data-center capex.

What about the currency?

The Korean won strengthened slightly. It was quoted at 1,336.7 per U.S. dollar as of 3:30 p.m., up 6 won from the previous stock trading session's close — a modest move that suggests the equity selloff was about stock-specific positioning rather than a broader flight from Korean assets.

Why does one CEO's exit move a market 5,000 kilometers away?

Because the AI economy has a single point of failure in perception, and for years that point has been Jensen Huang. Korea's largest export sector — semiconductors — sells into the compute buildout that Nvidia has orchestrated. Its internet platforms count Nvidia among their shareholders. When the person who coordinated that ecosystem departs, every downstream link reprices.

Friday's session put a number on that exposure: a 214-point round trip from the intraday high to the close, a net 550.5 billion won of foreign selling, and a 5.12 percent slide in the one Korean stock Nvidia actually owns a stake in.

The near-term direction now depends on two things the market can't control: how the AI ecosystem absorbs Nvidia's leadership transition, and what the upcoming U.S. producer price data says about the Federal Reserve's next move. Until both clear, the KOSPI's tech-heavy core looks exposed to more sessions like this one — and the defensive rotation into banks and autos that defined Friday is likely the template traders watch for.