KOSPI and Nikkei 225 plunge as AI stock selloff hits Asian markets

Asian stock markets fell sharply on Thursday, October 22, 2026, as renewed selling in AI-related shares overshadowed strong US tech earnings. South Korea's KOSPI dropped nearly 2% to 5,635, while Japan's Nikkei 225 fell about 1.6% to below 64,000 after an early gain. The decline followed the Bank of Korea holding its interest rate at 3% and Brent crude oil climbing above $110 per barrel. Samsung Electronics lost over 3% and SK Hynix nearly 4%, while Tokyo Electron fell 3.7%. Investors questioned whether strong chip demand justifies the costs of AI investments amid credit and profitability concerns. Broader Asian markets also weakened, with Hong Kong's Hang Seng down 2.1% and Shanghai's Composite losing 0.9%. Japan's reliance on fuel imports, combined with a weak yen around 158 per dollar, amplified energy cost pressures. The Bank of Japan is scheduled to meet on October 30.