South Korea's KOSPI falls 5% as AI stock sell-off deepens

South Korea's KOSPI index fell 5% on Tuesday as a deepening sell-off in AI stocks cut its 2026 gains to about 30%, down from roughly 116% at its June record close. Chip heavyweight SK Hynix headed for its lowest close since April, while data-center firm Elice plunged up to 32% on its trading debut. SK Hynix and Samsung have dropped 35% and 22%, respectively, with the index now trading about 39% below its peak. The decline follows a global rout that wiped out over $1 trillion from AI and semiconductor companies last week. Concerns over AI spending sustainability intensified after OpenAI reported September annualized revenue near $50 billion, below earlier projections, while industry leaders warned capital costs could constrain expansion.