The KOSPI fell 5.81 percent on June 26 as investors took profits following recent AI-driven gains, closing at 8,411.21.
The Korea Exchange activated a sell-side sidecar at around 11:13 a.m., halting program trading for five minutes after the KOSPI 200 futures fell more than 5 percent. The bourse later triggered a circuit breaker at 12:10 p.m. when the index dropped over 8 percent, pausing trading for 20 minutes.
Foreigners and institutions sold a net 4.6 trillion won and 3.8 trillion won respectively, while individuals bought a net 8.2 trillion won. Samsung Electronics closed down 5.3 percent at 339,500 won and SK hynix fell 8.36 percent to 2.67 million won.
"Investors are worried that too expensive memory chips would raise prices of end-use products and undermine demand for memory chips," said Han Ji-young, an analyst at Kiwoom Securities. The Korean won strengthened to 1,532 won per dollar.
