South Korea’s benchmark KOSPI triggered a market-wide halt after a sharp selloff in the country’s largest chip stocks, turning local AI-stock volatility into a global risk signal for equities and crypto. The index plunged 9.99% to close at 8,203.84, its steepest daily fall in more than three months. Samsung Electronics and SK Hynix each dropped more than 12%, wiping out billions in market value after foreign investors sold the same AI memory names that had carried the rally.