KOSPI Plummets Nearly 10% on 'Black Tuesday' Amid Foreign Sell-Off

by HYE YOUNG KO Posted : June 23, 2026, 16:56Updated : June 23, 2026, 16:56
KOSPI dropped nearly 10%, barely holding above 8,200, as employees work in a Hana Bank dealing room in Seoul on June 23. The index closed at 8,203.84, down 910.71 points (9.99%) from the previous trading day.
KOSPI dropped nearly 10%, barely holding above 8,200, as employees work in a Hana Bank dealing room in Seoul on June 23. The index closed at 8,203.84, down 910.71 points (9.99%) from the previous trading day. [Photo=Yonhap News]

On June 23, South Korea's stock market experienced a significant decline. Both the KOSPI and KOSDAQ triggered sell-off sidecars, with the KOSPI activating a circuit breaker, leading to extreme volatility throughout the trading session.
 
According to the Korea Exchange, the KOSPI closed at 8,203.84, down 910.71 points (9.99%) from the previous session. The index opened at 9,083.54, down 31.01 points (-0.34%), before deepening its losses during the day.

In the securities market, heavy selling by foreign and institutional investors dragged the index lower. Foreign and institutional investors sold a net 4.12 trillion won and 4.55 trillion won, respectively, while individual investors bought a net 8.58 trillion won.
 
Major stocks in the KOSPI also saw widespread declines. Hyundai Motor fell by 11.36%, while Samsung Electronics dropped 9.76%, SK Hynix 9.52%, Samsung Electro-Mechanics 9.43%, Samsung C&T 9.33%, HD Hyundai Heavy Industries 8.02%, LG Energy Solution 6.36%, Samsung Life Insurance 4.55%, SK Square 3.45%, and Samsung Biologics 1.70% all recorded losses.
 
The KOSDAQ also could not escape the downturn, closing at 891.52, down 76.88 points (7.94%). The index opened at 958.64, down 9.76 points (-1.01%), but later expanded its losses.
 
In the KOSDAQ market, foreign and institutional investors bought a net 258.8 billion won and 132.5 billion won, respectively, while individual investors sold a net 398.3 billion won.
 
Top stocks in the KOSDAQ also fell sharply. Rainbow Robotics recorded the largest drop at 11.87%, followed by Wonik IPS at 10.26%, EcoPro at 10.13%, EcoPro BM at 10.02%, IOTech at 9.75%, Rino Industrial at 7.79%, Juseong Engineering at 6.92%, HLB at 6.40%, Kolon TissueGene at 6.30%, and Alteogen at 5.56%, all showing declines.
 
By sector, the electronics and electrical sector saw the largest drop at 11.92%. This was followed by transportation equipment and parts at 8.87%, retail at 8.60%, machinery and equipment at 7.97%, IT services at 7.50%, chemicals at 6.30%, metals at 5.77%, insurance at 5.44%, finance at 5.12%, and pharmaceuticals at 3.23%, all experiencing declines.
 
Seo Sang-young, a researcher at Mirae Asset Securities, stated, "The valuation burden on large domestic semiconductor stocks, which have recently hit record highs, has increased. In particular, a strong wave of selling from foreign investors has intensified volatility during the session."

He added, "The desire for profit-taking among semiconductor companies has contributed to the index's decline, and this volatility is expected to continue for the time being."



* This article has been translated by AI.