South Korean stocks surge on AI rally after joint Japan-Korea intervention

On July 31, 2026, South Korea's Kospi index logged its largest daily gain on record, soaring 18% as investors piled back into AI-related stocks. The surge came after a rare joint intervention by Japan and South Korea in currency markets, which shook up the yen and won. The rally led Asia's tech sector, with Korean shares recovering sharply from a recent chip stock rout. The intervention aimed to tame wild swings in the currency markets, but the stock market defied those efforts with its historic jump.