Not financial advice. This is a weekly scoreboard from Seoul — the numbers and what moved them, on the KRX regular-session (15:30) close. It recommends nothing; the author holds none of the securities mentioned.
Last week (August 24–28) the KOSPI closed −1.79%. That one line hides almost everything that actually happened. The entire loss came on Friday. From Monday through Thursday the index fell hard and then climbed all the way back, so the net move across four sessions was close to zero. And the same week, the KOSDAQ rose 4.55%. This was not a week you can summarize with one index.
The scoreboard — week of Aug 24–28 (KRX close)
| Index | Prior close (Aug 21) | This week (Aug 28) | Weekly |
|---|---|---|---|
| KOSPI | 6,912.95 | 6,788.88 | −1.79% (−124 pts) |
| KOSDAQ | 801.94 | 838.41 | +4.55% (+36 pts) |
The daily KOSPI path — it broke on Monday, climbed back by Thursday, and gave it up again on Friday.
| Day | Close | Daily | What happened |
|---|---|---|---|
| Mon Aug 24 | 6,696.96 | −3.12% | Selling on Samsung’s shareholder-return plan |
| Tue Aug 25 | 6,742.74 | +0.68% | Fell as much as ~4% intraday, then recovered |
| Wed Aug 26 | 6,808.21 | +0.97% | Waiting on Nvidia earnings |
| Thu Aug 27 | 6,912.37 | +1.54% | Nvidia + Bank of Korea + Jackson Hole, all one morning |
| Fri Aug 28 | 6,788.88 | −1.79% | US chip-tariff pressure reported; profit-taking |
Reading inside the number
1) Thursday closed almost exactly where the week began. The Aug 27 KOSPI close (6,912.37) was a rounding error — 0.008% — from the prior trading day’s close (Aug 21, 6,912.95). Four sessions after a −3.12% Monday, the index had round-tripped all the way back to where it started, and it did so on the triple-event morning of Nvidia’s earnings, the Bank of Korea rate decision, and Jackson Hole (the Fed’s annual policy symposium). Which means the weekly −1.79% is, in practice, just Friday’s −1.79%. The other four days netted to near zero.
2) Two different shocks. Monday’s drop was domestic — Samsung Electronics’ “record” shareholder-return plan (₩90–110 trillion), announced after Friday’s close, came in below what the market wanted, and Samsung fell −8.70% on the first trading day after. Friday’s drop was external — reports that the US was pressing Korean chipmakers on US investment triggered profit-taking (selling to lock in gains) in semiconductors.
3) Samsung did not round-trip. The index recovered; Samsung did not. It fell to its Monday low (₩257,000), bounced to ₩266,000 by Thursday, then slid right back to that Monday low on Friday — a weekly −8.70% (₩281,500 → ₩257,000). Samsung is the largest holding in EWY (the iShares MSCI South Korea ETF), at roughly 21%. So even in a “quiet” index week, it was not a quiet week for a US investor holding Korea through EWY.
4) When the big caps hurt, the small caps rose. KOSPI −1.79% versus KOSDAQ +4.55% — a 6.3-percentage-point gap. The KOSPI is heavily weighted toward two chip names, Samsung and SK Hynix, and this week’s shocks landed squarely on them. The KOSDAQ — lighter on chips, heavier on smaller and biotech names — went the other way. Same “Korean market,” opposite report cards, depending on what you held.
🎩 Under the Gat. An index is not an average — it is a cancellation. “Down 1.8% on the week” doesn’t mean “nothing happened.” It means a Monday crash and a Thursday recovery erased each other, and only Friday’s reported chip-tariff shock was left standing. Put it to a US reader in one line: if the S&P were down 1.8% on the week but the whole loss was Friday, and the other four days swung hard and finished flat — would you call that week “−1.8%”? Not a perfect parallel — the KOSPI leans on two chip stocks far more than a US index does.
The one-line takeaway. Don’t remember this week by its index number. The KOSPI’s −1.79% was a round trip plus a reported Friday chip-tariff shock — and the real story was in Samsung (Monday’s −8.7%, never recovered) and in the 6.3-percentage-point split between the KOSPI and the KOSDAQ.
FAQ
Q. Why did the KOSPI fall last week?
On the week it was −1.79%, but the loss was concentrated in Friday, when reports of US pressure on Korean chipmakers’ US investment triggered semiconductor profit-taking. Monday through Thursday, a Monday Samsung crash and a Thursday recovery roughly cancelled out.
Q. Why did the KOSDAQ rise?
The KOSPI is concentrated in chip large-caps (Samsung, SK Hynix) that took this week’s hits; the KOSDAQ, lighter on chips, was less exposed and finished +4.55%.
Q. Why was Samsung’s shareholder-return plan a negative?
The ₩90–110 trillion figure is a range (not a fixed number), and part is an employee-incentive buyback (not a cancellation), so the actual return to shareholders read as below the headline — and Samsung fell −8.70% on the first session after. (More in the linked piece.)
Sources: KOSPI, KOSDAQ and Samsung Electronics closes, Aug 21–28, 2026 — Yahoo Finance ^KS11 / ^KQ11 / 005930.KS, sourced directly (currency KRW, exchange KSC/KOE = KRX); the Aug 28 index closes are the KRX regular-session values [primary]. Friday’s US chip-tariff reports — press [press-reported, not a confirmed single cause].
Written by Mr.Gat — TheGatBull
Korean market coverage from a Seoul-metro-based operator who reads the filings in the original language. Every price on this site is the KRX regular-session close (15:30 Seoul); every figure states whether it came from a primary filing, the press, or our own calculation. Drafts are AI-assisted, then verified against the original Korean documents and edited by a human before publishing.
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This is a weekly scoreboard, not investment advice. All figures are Korean won at the KRX regular-session 15:30 Seoul close, sourced directly from market data; no USD conversion is shown because the Aug 28 won close was not independently sourced. EWY is referenced for context, not as a recommendation.