South Korea's KOSPI dropped over four percent on July 20, 2026. Trading halted for twenty minutes after the plunge. Samsung and SK Hynix pulled the market deeper into the red. Soft appetite for AI memory chips weighed heaviest on tech names.
Markets then switched on a sell-side circuit breaker to ease the drop. Leveraged bets on surging AI stocks deepened the slide. Memory chip names slid further once U.S. markets had already sunk hard.