Kospi Posts Record 15% Daily Gain as Samsung and SK Hynix Surge Over 20%

South Korea's Kospi surged roughly 15% on July 31, 2026 — its largest single-day gain on record — after US markets bounced on July 30. An AI-sector rebound drove Samsung Electronics and SK Hynix each up over 20%. The rally follows a July rout that erased $2 trillion from the index since its June record high.