Seoul Shares Plunge Over 3% Amid Tech Sell-Off and Inflation Concerns

On October 12, 2026, Seoul shares fell by more than 3%, marking the fourth consecutive day of losses. The benchmark Korea Composite Stock Price Index (KOSPI) closed down 241.69 points, or 3.65%, at 6,384.24. The decline was primarily fueled by a massive sell-off in technology stocks amid rising inflation concerns and geopolitical tensions in the Middle East.

Analysts noted that the sell-off was exacerbated by the rebalancing of semiconductor-focused exchange-traded funds (ETFs) and worries that major companies like Samsung Electronics and SK Hynix may have completed their treasury stock purchases. Major tech stocks, including Samsung and SK Hynix, saw significant declines of 4.39% and 4.52%, respectively.

The market's downturn coincided with rising oil prices due to renewed conflicts in the Middle East, which further complicated inflationary pressures. As a result, investors are increasingly worried about the Federal Reserve's ability to manage inflation effectively.

Despite the overall market decline, some companies like shipping firm HMM and tobacco giant KT G managed to post gains. The Korean won also appreciated against the U.S. dollar, closing at 1,335.1 won per dollar, compared to the previous session's close of 1,342.8 won.