The KOSPI closed at 6,687.21 (+1.64%) and the KOSDAQ surged 2.95% as foreign and institutional investors bought heavily on Fed rate-pause signals, while retail investors sold about $3.3 billion. Semiconductors and crypto-linked names led; banks and biopharma lagged.
The KOSPI sank 3.99% to 6,562.72 as US-Iran clashes near the Strait of Hormuz pushed Brent above $90 and US yields hit multi-month highs. Samsung Electronics and SK hynix fell over 4%, while biotech names surged to Korea’s 30% daily limit.
KOSPI reversed a 1.28% intraday drop to close up 0.23% as Samsung Electronics and SK Hynix extended their buyback-driven rally amid renewed US-Iran tensions. KOSDAQ fell 1.56% with all ten of its largest stocks lower; retail investors bought while foreigners and institutions sold.
Korea’s KOSPI fell 1.79% to 6,788.88 as AI chip heavyweights saw post-Nvidia profit-taking, while the KOSDAQ held flat. Retail investors bought the dip as foreigners and institutions sold, with new Fed Chair Kevin Warsh’s first Jackson Hole speech looming after the close.
The KOSPI rose for a third straight day as Nvidia’s earnings beat lifted chipmakers and battery names surged on ESS tender hopes, but a mid-session Bank of Korea rate hike trimmed the benchmark’s gain to 1.53% at 6,912.37.
The KOSPI reversed an early dip to close at 6,808.21 (+0.97%) as Samsung Electronics (+1.75%) and SK Hynix (+0.60%) advanced on cheaper oil and lower US yields. The KOSDAQ ended flat, with Nvidia earnings, a Bank of Korea rate decision, and Jackson Hole all looming this week.
In Korea, a buyback lowers the share count for EPS purposes the moment the repurchased shares become treasury stock — but only cancellation makes that reduction permanent. Uncancelled shares can be resold or deployed for control, so the market prices a cancellation clause very differently from a bare repurchase pledge. Here is how to read the disclosures, the trust-contract loophole, and a checklist for judging any Korean buyback announcement.
Samsung Electronics’ record 110 trillion won shareholder-return plan fell short of market hopes, sending the stock down 8.7% and the KOSPI below 6,700. Rotation money lifted the KOSDAQ 1.4% as batteries and biotech rallied.
Seoul’s two markets went opposite ways: KOSPI recovered from a 1.35% opening drop to close up 0.88%, while KOSDAQ fell 4.63% and tripped its 32nd sidecar trading curb of 2026 as rising US yields hammered growth stocks.
The KOSPI jumped 5.89% to 6,852.58 after SK Hynix unveiled a record 40 trillion won buyback-and-cancellation plan. Foreign investors bought 1.7 trillion won of Seoul shares while the won hit its strongest level against the dollar in about 11 months.