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.
Korean chip stocks can fall the morning after an Nvidia beat because the move was pre-positioned: the reaction runs through the after-hours print, guidance, overnight US futures and after-hours moves in other chip names before the 09:00 Seoul open. Here is the full transmission chain, with a worked example reading real August 2026 foreign-flow data into a purely hypothetical earnings night — heavy selling that fades to near flat, a de-risking backdrop whose post-result implications can cut more than one way.
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.
The KOSPI plunged as much as 4.3% on overnight US chip weakness before Samsung Electronics and SK Hynix powered an afternoon reversal, closing up 0.68% at 6,742.74. Foreign investors sold heavily into the dip while retail bought. Nvidia’s earnings loom Wednesday.
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.
A 2x daily-reset product does not double your holding-period return: after a +10% then -10% two-day swing, the underlying is down 1% but the 2x product is down 4%. Here is the reset mechanism, the decay math on volatile Korean names like Samsung Electronics and SK Hynix, and the FSC/KRX rules that govern these products.
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.