South Korean stocks staged their most dramatic single-day recovery in recent memory on June 9, with the KOSPI index surging 8.2% after a punishing selloff that had erased 15% from its recent peak over just three trading sessions.
The rebound was powered almost entirely by the country’s two memory chip titans. Samsung Electronics climbed as much as 9.3%, while SK Hynix, the company that crossed the $1 trillion market cap threshold just weeks earlier, rocketed more than 15% in a single session.
What triggered the selloff, and why it reversed
The day before, June 8, had been ugly. The KOSPI plunged 8.8% in a wave of selling so violent it triggered a 20-minute trading halt. The catalyst was underwhelming guidance from US semiconductor giant Broadcom, which sent a chill through every market with meaningful exposure to the AI chip supply chain.
For Samsung and SK Hynix, those fundamentals remain anchored in surging demand for high-bandwidth memory chips, the specialized silicon that makes AI training and inference possible at scale.
