Circuit Breakers Triggered on KOSPI and KOSDAQ Amid Semiconductor Plunge

On the morning of July 28, 2026, 'Level 1 circuit breakers (temporary trading halt)' were triggered simultaneously in the KOSPI and KOSDAQ markets due to a plunge in semiconductor-related stocks. In the early session of the day, sell-side programs were triggered first in both markets, followed by sustained index declines that led to the activation of the circuit breakers. A circuit breaker is activated if the index falls by more than 8% from the previous day's closing price for one minute. Trading for all stocks is halted for 20 minutes, followed by 10 minutes of single-price auction trading before resumption. This marks the third time this year that both major markets have faced simultaneous circuit breakers, following March 4 and June 8.

During the session, the KOSPI index recorded a plunge of 694.62 points (10.28%) to 6061.13, while the KOSDAQ index fell 61.93 points (8.10%) to 702.93. Top market-cap stocks experienced sharp declines, with Samsung Electronics down 12.60%, SK Hynix down 13.55%, SK Square down 14.78%, and Samsung Electro-Mechanics down 17.51%.

In the KOSPI market, individual investors net bought KRW 3.5561 trillion, while foreigners and institutions net sold KRW 3.3985 trillion and KRW 179.2 billion, respectively. Similarly, in the KOSDAQ market, individuals net purchased KRW 146.3 billion, whereas foreigners and institutions net sold KRW 71.1 billion and KRW 74.5 billion, respectively.