South Korean shares ended a turbulent week slightly lower despite staging their strongest one-day rally on record on July 31, as extreme swings in semiconductor stocks dominated trading.
The benchmark Kospi closed at 6,595.45 on July 31, down about 1.4% from the previous Friday’s 6,690.62. During the week, the index moved from modest gains to a deep three-day rout before rebounding sharply in the final session.
The Kospi began the week 0.97% higher at 6,755.75 on July 27. It then plunged 10.84% the following day as a global chip sell-off and concerns over growing Chinese competition hammered Samsung Electronics and SK hynix.
Losses extended into July 29, when the index fell another 5.98% to 5,663.24 after SK hynix’s earnings failed to meet elevated market expectations and leveraged investors rushed to exit positions. It slipped a further 1.23% on July 30, taking the three-session decline to more than 17%.
However, the trading session on the last day of the month delivered a dramatic reversal as the Kospi soared 1,001.89 points, or 17.91%, after strong earnings and cloud-growth forecasts from major US technology companies eased concerns that heavy artificial intelligence (AI) investment was failing to produce returns.
Samsung Electronics surged 26.81%, while SK hynix hit its daily limit with a 29.95% jump, helping the index reclaim the 6,500-point level.
The week highlighted the Kospi’s growing sensitivity to shifts in AI sentiment, with its heavy concentration in semiconductor giants and leveraged investment products amplifying movements in both directions.
