South Korea’s KOSPI index plunged 8.3% on June 8, closing at 7,484.41, as investors dumped semiconductor stocks amid concerns of an overheated market. The decline triggered circuit breakers, halting trading for 20 minutes.
Samsung Electronics dropped 10.2%, while SK Hynix fell 7.7%. Together, they account for a substantial portion of the KOSPI's gains, approaching a $1 trillion market cap at their peak.
The sell-off was initiated by Broadcom's disappointing forecasts, causing the Philadelphia Semiconductor Index to drop over 10%, which affected global chip stocks. Additionally, strong US jobs data heightened expectations for Federal Reserve rate hikes.
The KOSPI peaked at 8,801.49 on June 2, but by June 8, it had fallen approximately 15%.
Foreign investors reported net selling of 355 billion won ($231 million) on June 8, marking 21 consecutive sessions of selling. Despite the downturn, the KOSPI remains up 78% year-over-year after a 76% increase in 2025, its best performance since 1999. The Korean won also hit a near 17-year low, prompting emergency meetings among financial authorities.