Kospi Plunges 10.84% as Samsung and SK Hynix Collapse, Hitting Global Chip Stocks

South Korea's Kospi plunged 10.84% to 6,023.66 on July 28, 2026 — its worst day since early March — as SK Hynix fell 14.7% and Samsung 13.4%, triggering two circuit-breaker halts. The selloff spread to Wall Street, where Intel, AMD, and Seagate each dropped over 4%. Catalysts: China's mass production of homegrown DUV lithography tools and Nvidia's reported $250bn OpenAI datacentre discussions.