Kospi Slips 0.61% as Nvidia Leadership Crisis Splits Korea's Chipmakers

South Korea's Kospi closed at 5,342.73 on 12 November, down 32.63 points or 0.61%, snapping a two-day rally that had added 7.1% to the index, Korea JoongAng Daily reported. The reversal came after the Wall Street Journal reported that Nvidia's board was preparing to remove CEO Jensen Huang, sending Nvidia down more than 8% in after-hours trading.

The session's defining trade was the split between Korea's two memory giants. Samsung Electronics rose 0.97% to 208,000 won. SK Hynix fell 1.80% to 1,254,000 won. The divergence tracked each chipmaker's exposure to Nvidia's deepening leadership crisis.

How did the morning reverse?

The Kospi opened at 5,385.94 and climbed as high as 5,458.84 during the morning session, boosted by CoreWeave's strong Q3 earnings and a 2.9% gain in Nvidia during regular US trading, Seoul Economic Daily reported. Samsung Electronics and SK Hynix gained as much as 3.88% and 2.58% respectively before the WSJ report drained sentiment from Korean chip stocks through the afternoon.

Options expiry day added selling pressure. Institutions sold a net 691.1 billion won in the Kospi market, according to reports from JoongAng, Aju Press and MoneyToday.

Lee Kyung-min, head of the FICC Division at Daishin Securities, said: "the Kospi index continued to weaken as it digested uncertainty stemming from the scandal related to Nvidia CEO Jensen Huang," MoneyToday reported.

Why did Samsung and SK Hynix diverge?

The gap came down to Nvidia exposure. SK Hynix's exposure to Nvidia's high-bandwidth memory (HBM) orders is relatively larger than Samsung's, according to Aju Press, and that weighting punished the stock once the Huang report landed.

Foreign investors priced the divergence directly. They bought a net 744.9 billion won of Samsung Electronics and sold a net 872 billion won of SK Hynix, according to Seoul Economic Daily. Samsung Electro-Mechanics, another company with significant Nvidia exposure, fell in the 4% range, MoneyToday reported.

Samsung's resilience owed something to its broader product mix. Memory is a large part of Samsung's semiconductor business, but the company also sells smartphones, displays and consumer electronics, diluting the Nvidia-specific risk that hit SK Hynix directly.

Is this a demand shock for memory?

Not necessarily. The Huang crisis is a governance event, not a demand signal. Nvidia's Q3 earnings report, scheduled for 17 November, will give investors a chance to assess the company's data-centre business and whether demand for its AI chips remains strong.

The outlook for AI infrastructure spending and memory-chip demand remains an important factor for investors assessing Nvidia's supply chain. One session of selling does not settle that question.

Did the selloff spread beyond Seoul?

It did. Japan's market followed the same downward path. Kioxia, the memory-chip maker, fell 2.83%, while SoftBank Group declined 3.04% in Tokyo trading, according to TradingKey.

The Nikkei 225 opened higher but gave back gains through the afternoon, following the same Nvidia-driven reversal that hit Seoul. The index closed down 0.70% at 60,819.36, according to Aju Press.

The pattern across both markets suggests investors are repricing key-person risk across Nvidia's supply chain, from HBM suppliers in Seoul to memory and AI-investment plays in Tokyo — although these sessions alone do not establish whether investors have changed their longer-term outlook for AI demand. Nvidia's 17 November earnings report now stands as the next hard datapoint for whether the supply-chain repricing extends or reverses.