Woofun AI data shows that the Nikkei 225 Index closed at 66,835.54 points, marking a decline of 1,915.97 points or 2.79%, while Japanese stock storage firm Kamen Rider fell 14%. The South Korean KOSPI Index dropped 466.06 points to 6,818.35, a 6.4% decrease, with SK Hynix down 11% and Samsung Electronics falling 8%. Authorities in South Korea indicated they will soon unveil measures to address market volatility exacerbated by leveraged ETFs linked to these semiconductor stocks.