KOSPI Circuit Breaker Followed by Sell-Sidecar; Semiconductor Stocks Plunge Around 10%

[Financial News] After the KOSPI plunged more than 8% early in the session, triggering a circuit breaker, a sell-sidecar was activated shortly after trading resumed. Concerns over slowing investment in AI infrastructure sparked heavy selling, particularly in large-cap semiconductor stocks, prompting a series of market safety measures.
According to the Korea Exchange (KRX), a sell-sidecar was activated on the KOSPI market at 9:34 a.m. on the 6th. The front-month mini KOSPI 200 futures contract plunged 6.77%, from a reference price of 837.80 to 781.00, meeting the trigger threshold. This was the 30th time a sell-sidecar has been activated on the KOSPI market this year.
A sell-sidecar on the KOSPI market is triggered when the front-month KOSPI 200 futures contract remains at least 5% below its reference price for one minute. When triggered, the effectiveness of sell orders for program trading is suspended for five minutes and then automatically restored.
Earlier, at 9:03 a.m., the KOSPI fell 459.19 points (8.52%) from the previous trading day’s close of 5,383.80 to 4,924.61, triggering a Level 1 circuit breaker. It was the 11th activation this year and the 17th on record.
When a Level 1 circuit breaker is triggered, trading in all issues listed on the KOSPI market, except bonds, is halted for 20 minutes. Trading then resumes after a 10-minute single-price auction. The exchange cited concerns about slowing investment in AI infrastructure, among other factors, as the reason for the activation that day.
The index plunge was led by large-cap semiconductor and electronics stocks. As of 10:10 a.m. that day, SK hynix was down 10.76% at 1,128,000 won, while Samsung Electronics was down 8.29% at 184,800 won. Samsung Electro-Mechanics fell 12.82%, Samsung Electronics preferred shares fell 7.92%, and SK Square fell 11.12%.
A sell-sidecar was also activated on the KOSDAQ market at 9:06 a.m. KOSDAQ 150 futures plunged 7.84% from the previous trading day, while the KOSDAQ 150 Index fell 8.10%. With market stabilization measures activated one after another in both the KOSPI and KOSDAQ markets, investor sentiment was extremely subdued early in the session.


[email protected] Bae Han-geul Reporter