Seoul shares crash over 7 pct on chip rout amid AI, inflation woes

South Korean shares suffered a sharp decline of over 7 percent on Thursday, as major chipmakers continued to experience losses amid mounting doubts about the viability of AI-driven investments and the Federal Reserve's decision to raise interest rates. The Korean won also weakened against the US dollar. The Korea Composite Stock Price Index (KOSPI) opened 5.59 percent lower and saw its losses multiply, falling 454.59 points, or 7.57 percent, to close at 5,554.22, marking its seventh consecutive day of decline.

The KOSPI had been in a prolonged slump since September 2024. The significant drop triggered the Korea Exchange (KRX) to activate a sell-side sidecar, suspending program selling for five minutes as KOSPI 200 futures plummeted more than 5 percent for at least a minute. This was followed by a circuit breaker at 12:38 p.m., pausing trading on the main bourse for 20 minutes after the KOSPI slumped more than 8 percent from the previous session's close.

The market downturn was preceded by a drop in US stocks on Thursday as renewed worries over the sustainability of AI-related spending and higher-than-anticipated September inflation data dampened investor confidence. The US Consumer Price Index (CPI) increased by 0.6 percent in September, its steepest monthly rise since April, raising concerns that ongoing inflation could prompt the Fed to increase interest rates.