Summary:
South Korea’s KOSPI plunged 8.52% below 5,000 on November 6, triggering a 20-minute trading halt. Semiconductor stocks, including Samsung Electronics and SK Hynix, led the selloff amid concerns over AI spending and US data-centre restrictions. The index later partially recovered.
Seoul's KOSPI index fell more than 8 percent in early trading Friday, Nov. 6, 2026, sliding below the 5,000 point level as heavy selling hit semiconductor and technology stocks.
The drop triggered a market-wide circuit breaker that halted trading for now. Part of the selloff was due to worries about artificial intelligence investments and potential limits on the building of US data centers.
KOSPI Drops Over 8% in Early Trading
The KOSPI dropped 2.24% to end at 5,263.26, from the previous session’s close of 5,383.80.
Minutes later sales were picking up pace.
The benchmark index fell 8.52 percent to 4,924.61 at around 9:03 a.m. Korean time, hitting the first-stage circuit breaker.
The index then fell to around 4,920 in the first bout of selling, its first dip below 5,000 since early 2026.
The Korea Exchange halted trading for 20 minutes under its market protection mechanism.
The circuit breaker is meant to temporarily stop trading when an index suffers an extremely sharp decline, allowing market participants time to digest the rapidly changing conditions.
The tumble followed the KOSPI’s 5.28% plunge on Thursday, extending losses for a second consecutive session.
What caused the South Korean stock market to crash?
The selloff followed a sharp drop in US technology stocks on November 5.
The Nasdaq Composite was down 5.52%, and the Philadelphia Semiconductor Index was off more than 12%.
Investors worried about the profitability of artificial intelligence investments led to heavy selling in companies that supply advanced chips and related infrastructure.
The outcome of the US midterm election has created uncertainty regarding future government restrictions on the development of data centers.
Any slowdown in building data centers would cut demand for high-bandwidth memory chips, advanced processors and other semiconductor products.
South Korea has a large exposure to the global semiconductor industry, and its equity market is vulnerable to shifts in global technology spending.
The opening session saw some more selling pressure from foreign institutions as well.
Samsung Electronics, SK Hynix Lead the Fall
Among the biggest losers were South Korea’s largest makers of semiconductors.
Samsung Electronics (KRX: 005930) dropped nearly 10% to 181,400 won in early trade.
SK hynix (KRX: 000660), a supplier of high-bandwidth memory for AI computing systems, fell about 11.7% to around 1.12 mn won.
Both companies are big components of the KOSPI and have a strong influence on the index’s moves.
Other big companies also felt the weight of selling pressure.
Hyundai Motor (KRX: 005380) was down almost 7% in the first selloff, while LG Energy Solution (KRX: 373220) was down almost 4%.
The technology-heavy KOSDAQ index also fell as selling spread beyond the biggest semiconductor companies.
KOSPI Recoups Some Losses After Trading Suspension
The KOSPI later clawed back some of its earlier losses with domestic institutional and retail buying emerging.
The index was back above 5,100, trading around 5,144, down some 4.45%, by about 11:28 am Korean time.
The rebound capped the initial crash, but technology shares continued to be under pressure.
The intraday rebound doesn't erase the fact that the index had dropped below the 5,000 mark and triggered a circuit breaker earlier in the session.
Moves in the South Korean market reflect the country’s sensitivity to the global semiconductor cycle.
Further developments in US tech regulation, AI infrastructure spending and foreign institutional flows will be important for the Korean equity market.
KOSPI intraday developments on Nov. 6, 2026, including Korea Exchange trading curbs and subsequent recovery. Figures are derived from intraday trading, not a final closing loss.
