Korea's chip-heavy KOSPI drops 5% weekly while Japan's Nikkei gains 1.2%

KOSPI fell 0.5%, heading for a 5% weekly loss, while Nikkei 225 slipped 0.9% but stayed up 1.2% weekly, exposing Asia's growing Korea-Japan divergence. Korea's heavy concentration in memory chips—Samsung and SK Hynix make up about 53% of KOSPI—amplified the selloff after US semiconductor stocks tumbled, raising doubts about AI pricing. Japan's index showed resilience, though AI-linked names weakened and a weak yen supports exporters. Investors await Friday's US jobs report and rising oil prices, which could determine whether the divergence narrows or deepens. KOSPI faces its seventh straight weekly loss; yen trading near 158.5.