South Korea's KOSPI Plunges 8% Triggering Circuit Breakers on US Inflation Data

Key Facts

1South Korea's stock market triggered circuit breakers following a sharp 8% plunge.

2Surprise U.S. inflation data exacerbated the sell-off in Korean semiconductor stocks.

South Korea's stock market triggered circuit breakers following a sharp 8% plunge. 247wallst.com reported that surprise U.S. inflation data exacerbated a massive sell-off in semiconductor stocks, with Samsung Electronics falling 5.17% and SK hynix dropping 11.06% in early trading on October 15, 2026.

U.S. inflation pressures, which saw September prices rise 3.7% annually against a 3.6% forecast, fueled concerns over prolonged high interest rates. According to trading data from October 15, 2026, foreign investors were net sellers of 284.7 billion won immediately after the open, driving the KOSPI index down to approximately 5,540 by midday, leaving it roughly 41% below its June 2026 record high.