Circuit breaker activated on Kospi for 4th time of the year as shares plunge 8 percent
Among the market's largest stocks, SK hynix fell 11.55 percent to 2.58 million won while Samsung Electronics was down 8.77 percent at 322,500 won when trading was halted.
An electronic display board shows the Kospi in Hana Bank's trading room in Jung District, central Seoul, on June 23.NEWS1
A circuit breaker was activated on Tuesday at 2:33 p.m. to halt all trading on Korea's main stock market for 20 minutes after the benchmark Kospi plunged more than 8 percent.
A first-stage circuit breaker was activated after the Kospi fell 8.07 percent from the previous session to 8,378.25, according to the Korea Exchange (KRX).
The bourse closed at 8203.84, down 9.99 percent from the previous session, according to the KRX.
A circuit breaker is a mechanism that temporarily suspends trading in stocks and related derivatives to cushion the market from severe shocks during sharp declines. It is activated when the index falls at least 8 percent from the previous day's close and remains at that level for one minute.
It was the fourth circuit breaker of the year, following previous activations on March 4, March 9 and June 8. Trading resumed at approximately 2:53 p.m.
A second-stage circuit breaker can also be activated if, after trading resumes, the index falls more than 15 percent from the previous day's close and remains at least 1 percentage point below the level that triggered the first-stage suspension for one minute. Like the first stage, it halts trading for 20 minutes.
The Kospi opened 0.34 percent lower from the previous session at 9,083.54 and fluctuated throughout the morning. It briefly recovered above the 9,100 level before extending its losses and falling into the 8,600 range. Selling accelerated in the afternoon.
Foreign and institutional investors sold a net 4.12 trillion won ($2.68 billion) and 4.55 trillion won, respectively. Retail investors bought 8.58 trillion won worth of shares.
Among the market's largest stocks, SK hynix fell 12.47 percent to close at 2.56 million won, the steepest drop since Dec. 24, 2008, during the global financial crisis, when it tumbled 12.73 percent, according to the KRX.
Samsung Electronics was down 8.77 percent at 322,500 won when trading was halted. At close, Samsung Electro-Mechanics had slid 10.68 percent, Samsung Electronics preferred shares lost 9.6 percent and SK Square declined 7.01 percent.
The Kosdaq also tumbled, closing at 891.52, down 7.94 percent from the previous session.
The tech-heavy index opened 1.01 percent lower at 958.64 and continued to decline throughout the session. Losses widened to more than 7 percent in the afternoon, pushing the index below the 900 mark.
An electronic display board shows the Kosdaq at 891.52 at Hana Bank's trading room in Jung District, central Seoul, on June 23.NEWS1
Foreign and institutional investors were net buyers of Kosdaq shares worth 258.8 billion won and 132.4 billion won, respectively, while retail investors sold a net 398.3 billion won.
Most large-cap Kosdaq stocks were also in negative territory, including Alteogen, down 4.99 percent; Jusung Engineering, down 6.92 percent; EcoPro BM, down 9.48 percent; EcoPro, down 10.04 percent; and Rainbow Robotics, down 12.22 percent.
Earlier on Tuesday, sell-side sidecars — a mechanism that temporarily suspends program trading for five minutes — were triggered for both bourses.
A sell-side sidecar on the Kosdaq market was activated at 11:37 a.m. after sharp declines in the Kosdaq 150 futures and spot indexes, according to the Korea Exchange.
At the time of the sidecar activation, the Kosdaq 150 futures index had fallen 6.01 percent from the previous session to 1,667.80, while the Kosdaq 150 spot index was down 5.33 percent, or 93.26 points, to 1,653.67.
The Korea Exchange logo is displayed in Yeouido, Yeongdeungpo District, western Seoul in this file photoYONHAP
A Kosdaq sell-side sidecar is triggered when both the Kosdaq 150 futures index falls at least 6 percent, and the Kosdaq 150 spot index drops at least 3 percent from the previous session’s close for at least one minute.
Just minutes later, at 11:40 a.m., a sell-side sidecar was also activated on the main Kospi market after the Kospi 200 futures index declined sharply. Program sell orders were again suspended for five minutes.
The Kospi 200 futures index was down 5.12 percent from the previous session's close at 1,407.54 when the sidecar was triggered. A sell-side sidecar on the Kospi market is activated when the Kospi 200 futures index falls at least 5 percent and remains at that level for one minute.
It was the first simultaneous activation of sell-side sidecars in the Kospi and Kosdaq markets since June 8.
Updated, June 23, 2026: Added details about the circuit breaker, closing prices for stocks.
This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
