5 of 11 all-time circuit breakers triggered in 2026 alone

Samsung Electronics, SK Hynix lead broad selloff among top-cap stocks

Kosdaq also falls over 4% amid extreme volatility

The Kospi and other market indicators are displayed on a screen at the Hana Bank dealing room in Jung-gu, Seoul, on Friday. [Yonhap]
The Kospi and other market indicators are displayed on a screen at the Hana Bank dealing room in Jung-gu, Seoul, on Friday. [Yonhap]

The Kospi triggered a circuit breaker Friday after plunging more than 8% intraday, halting trading on the main bourse for the fifth time this year and the eleventh time in history.

With half of all circuit breakers ever triggered now concentrated in 2026 alone, analysts warn that volatility in the South Korean equity market has reached an extreme.

Korea Exchange said trading on the securities market was suspended for 20 minutes beginning at 12:10:12 p.m. Friday.

The halt was triggered after the Kospi fell more than 8% from the previous session's closing level and held that decline for one continuous minute.

All stocks listed on the securities market were temporarily suspended, as were futures and options markets linked to equities.

At the time the circuit breaker was triggered, the Kospi stood at 8,198.33, down 731.97 points, or 8.19%, from the previous session. The index retreated as far as 8,126.84 at one point.

Earlier, at around 11:12:12 a.m., a sell-side sidecar was also activated after the KOSPI 200 futures index fell more than 5%.

Friday's halt was the fifth circuit breaker triggered on the Kospi this year.

The previous four came amid the US-Iran crisis (March 4), a surge in oil prices driven by Middle East tensions (March 9), a sharp drop in semiconductor stocks on fears of US interest rate hikes (June 8), and a broad selloff in US technology shares (Monday). The repeated triggers reflect a pattern in which the Kospi's steep rally this year has been accompanied by sharply rising volatility.

As of 1:14 p.m., the index was down 7.30% at 8,278.21. The two semiconductor heavyweights underpinning the domestic market — Samsung Electronics and SK Hynix — were both deep in the red. Samsung Electronics was trading down 7.67% at 331,000 won ($214), while SK Hynix had fallen 9.05% to 2,653,000 won.

Every other top-cap stock was also lower: SK Square (-11.01%), Samsung Electronics preferred shares (-6.60%), Samsung Electro-Mechanics (-0.95%), Hyundai Motor (-6.56%), Samsung Life (-4.81%), Samsung C&T (-5.97%), LG Energy Solution (-7.10%) and Samsung Biologics (-4.47%).

On the securities market, retail investors were net buyers of 5.3669 trillion won, while foreign and institutional investors were net sellers of 4.7726 trillion won and 699.5 billion won, respectively.

Han Ji-young, a researcher at Kiwoom Securities, said concerns that rising memory chip prices could dampen end demand were weighing on sentiment — not only among device makers such as Apple but also by raising the prospect of reduced investment by hyperscalers. "The burden of profit-taking after the Kospi's sharp short-term rebound, along with the concentration of flows into semiconductor stocks, also appears to have contributed," Han said.

However, Han added that fears of a decline in memory chip demand were "excessive," saying that the concentration of flows into semiconductor stocks and the resulting widening of supply-demand volatility explained most of the day's sharp drop.

The Kosdaq was also deep in the red at the same time, falling 4.26% to 849.97. Notable decliners included Alteogen (-7.20%), Ecopro BM (-8.06%), Ecopro (-6.86%) and Rainbow Robotics (-7.95%).


jiyun@heraldcorp.com