KOSPI falls below 5,000, circuit breaker hit as Samsung, SK Hynix slide
By Rohit SharmaMarkets Analyst, Peepals Business
Representative image: Tumisu / Pixabay
The KOSPI fell more than 8% and below 5,000 on 6 November 2026, triggering a circuit breaker, after a Wall Street AI chip sell-off.
What Happened
South Korea's main stock index, the KOSPI, fell more than 8% in morning trade on Friday, 6 November 2026 and dropped below 5,000 for the first time in about 10 months, triggering a circuit breaker, an automatic pause in trading meant to stop panic selling. The fall followed a heavy sell-off of artificial intelligence (AI) and chip shares on Wall Street on Thursday, 5 November, when the Nasdaq 100 index lost about 6.4%. Shares of Samsung Electronics and SK Hynix, the two Korean memory-chip makers that supply AI chip companies, fell about 10% and 12% respectively.
Key Facts
- KOSPI: fell more than 8% in early trade on 6 November (one report put the fall at 8.55% at one point) and slipped below 5,000 for the first time in about 10 months.
- Circuit breaker: trading was halted; reports said it was the tenth time this year that South Korea's exchange operator had used a circuit breaker for local markets.
- Samsung Electronics: down 9.98% to 181,400 won in morning trade.
- SK Hynix: down 11.79% to 1,115,000 won in morning trade.
- Wall Street on 5 November: the Nasdaq 100 fell about 6.4% (one report says 6.3%), erasing more than $2 trillion in market value; the Philadelphia Semiconductor index fell about 12%; Nvidia closed 9.26% lower at $181.60.
- Reasons cited: worries that new Democratic majorities in US states and Congress after the 3 November midterm elections could make large AI data centres harder to build, and wider doubts about whether heavy AI spending will pay off.
- Analyst view: a researcher at Kiwoom Securities said the scope of any regulation, whether projects will actually be delayed, and any fall in AI demand had not yet been confirmed.
Why It Matters
Korea's stock market depends heavily on two companies, Samsung Electronics and SK Hynix, both of which sell high-bandwidth memory, the fast memory chips used alongside AI processors made by companies such as Nvidia. When investors in New York begin to doubt the AI building boom, Seoul feels it almost at once. Friday's fall shows how closely Asian markets are now tied to the fortunes of a handful of US AI companies.
The trigger this time was political as much as financial. After the US midterm elections, investors began to price in the risk that new state and federal lawmakers could restrict power-hungry data centres. AI companies have been spending heavily on such facilities, and any delay would reduce demand for the chips Samsung and SK Hynix make.
The circuit breaker is a reminder of how volatile the AI trade has become. Using it ten times in one year shows how often Korean markets have swung sharply. For Indian investors, the episode matters because global funds that hold Asian technology stocks often adjust their positions across the region together.
These are intraday figures from the morning session. Closing levels could differ.
Peepals calculation: Samsung's fall of 9.98% to 181,400 won implies a previous close of about 201,500 won (181,400 ÷ 0.9002). SK Hynix's fall of 11.79% to 1,115,000 won implies a previous close of about 1,264,000 won (1,115,000 ÷ 0.8821). Nvidia's 9.26% drop to $181.60 means it closed the day before at about $200.13 (181.60 ÷ 0.9074). Our calculation from the reported figures.
| Market or stock | Move reported | Level reported |
|---|---|---|
| KOSPI (6 Nov, morning) | down more than 8% | below 5,000 |
| Samsung Electronics | down 9.98% | 181,400 won |
| SK Hynix | down 11.79% | 1,115,000 won |
| Nasdaq 100 (5 Nov) | down about 6.4% | not given |
| Nvidia (5 Nov close) | down 9.26% | $181.60 |
Impact
Short-term: Korean investors face steep paper losses, and the halt gives markets a pause to absorb the news. Other Asian markets with large chip companies are also under pressure.
Long-term: If US rules on data centres do tighten, demand for AI memory chips could grow more slowly than investors had expected, hurting the earnings outlook for Korea's two biggest companies.
Who is affected: Investors in Korean and other Asian technology shares; Samsung Electronics and SK Hynix and their suppliers; global funds with large AI holdings; and companies planning AI data centres in the United States.
Key Takeaway
The KOSPI fell more than 8% and below 5,000 on 6 November 2026, triggering a circuit breaker, after a Wall Street AI sell-off driven by fears of US curbs on data centres.
Questions and Answers
Why did the KOSPI fall on 6 November 2026?
It followed a heavy sell-off of AI and chip shares on Wall Street on 5 November, linked to worries that US lawmakers elected in the midterms could restrict new data centres, and to doubts about returns on AI spending.
What is a circuit breaker in the stock market?
It is an automatic halt in trading when an index falls by a set amount, giving investors time to pause. Reports said it was the tenth time this year South Korea's exchange used one.
How much did Samsung and SK Hynix shares fall?
In morning trade, Samsung Electronics fell 9.98% to 181,400 won and SK Hynix fell 11.79% to 1,115,000 won.
How much did the Nasdaq fall on 5 November?
The Nasdaq 100 fell about 6.4%, and Nvidia closed 9.26% lower at $181.60.
Disclaimer: Prepared by the Peepals newsroom from publicly available sources with AI assistance. Information is accurate to the best of our knowledge at the time of publication and may change. Images may be representative. Not professional advice. Report an error via our contact page.
By Rohit Sharma, Markets AnalystCovers Markets Watch and more for Peepals Business. All stories by Rohit Sharma
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Rohit Sharma is a pen name of the Peepals Global Editorial Team, which researches, fact-checks and publishes every story. The portrait is an illustration.
