카테고리
실마리 일지

KOSPI -1.79% · KOSDAQ +4.55% for the week — one Monday decline split the five days — Korea Market Week in Review, Aug 29, 2026

KOSPI fell -3.12% on Monday, then rose three sessions running — +0.68% on Tuesday, +0.97% on Wednesday and +1.53% on Thursday — before falling -1.79% on Friday.KOSDAQ ran differently: up +1.42% on Monday and +1.70% on Tuesday, down -0.03% on Wednesday, then +1.30% on Thursday and +0.09% on Friday —

The Silmari
A daily data newsletter on the Korean stock market — silmari, ‘a clue: the loose end that unravels the knot’
◈ Weekend Silmari — Week in Review 12:002026.08.29 Sat · No. 26Sentiment: Neutral — as of Friday (08.28) close
◈ Weekend — Week in Review · published 12:00 KST · week ended Friday
01 · Weekly verdictAs of Friday (08.28) close — confirmed

This week in review

A window on where the market moved over the week

KOSPI -1.79% · KOSDAQ +4.55% for the week — one Monday decline split the five days

Down -3.12% on Monday, then four sessions of recovery — and KOSPI still ended the week lower

Headlines by day — the week in five sentences
Tue (08.25)Semiconductors fell sharply overnight, and Korea rose against them
Wed (08.26)The index rose while retail investors sold KRW 2tn
Thu (08.27)The close did not settle into a single figure by evening — a first in nine sessions
Fri (08.28)A day staked to the upside closed at -1.79% — the two indices parted ways

KOSPI fell -3.12% on Monday, then rose three sessions running — +0.68% on Tuesday, +0.97% on Wednesday and +1.53% on Thursday — before falling -1.79% on Friday.KOSDAQ ran differently: up +1.42% on Monday and +1.70% on Tuesday, down -0.03% on Wednesday, then +1.30% on Thursday and +0.09% on Friday — four of five sessions higher.Monday alone set the KOSPI’s week. The gains of the four sessions that followed did not add up to that one decline, and the week closed at -1.79%.That the two indices looked in different directions all week is the other shape of it — KOSPI ended negative while KOSDAQ ended +4.55%.

02 · Weekly numbersAs of Friday (08.28) close — confirmed

The week in numbers

A window measuring the week’s change, its range and where it sits within the year

KOSPI’s weekly -1.79% ranks 11th from the bottom among this year’s 34 weeks

Week = Monday open through Friday close · ranks vs. completed weeks of 2026 · source: FinanceDataReader
ItemKOSPIKOSDAQRank this year
Weekly change−1.79%+4.55%KOSPI: rank 24 of 34 weeks
Weekly high–low range+9.16%+7.54%KOSPI: rank 22 of 35 weeks
Friday close6,788.88838.41
Against the pastThe KOSPI’s weekly change of -1.79% ranks 11th from the bottom among this year’s 34 weeks, and its weekly high-low range of 8.5% ranks 26th by size.KOSDAQ’s weekly +4.55% ranks 30th from the bottom over the same 34 weeks, with a high-low range of 7.4% ranking 22th by size.The change sits low while the range sits mid-table — this reads less as a week of wide swings than as a week with one large one-way session.
03 · Weekly flowsAs of Friday (08.28) close — confirmed

Weekly flows — who bought and who sold

A window on how much foreign investors, retail investors, investment firms and pension funds each bought and sold over the week

Foreign investors sold a net -KRW 8,317.1bn for the week — the largest of the four groups

KOSPI market net buying · in won · source: Korea Exchange
DayKOSPIForeign investorsRetail investorsInvestment firmsPension funds
Mon (08.24)−3.12%−₩3.67tn+₩3.32tn−₩689.5bn+₩4.4bn
Tue (08.25)+0.68%−₩3.81tn+₩1.05tn+₩1.13tn+₩23.4bn
Wed (08.26)+0.97%−₩114.8bn−₩2.25tn+₩770.6bn−₩33.9bn
Thu (08.27)+1.53%+₩133.3bn−₩1.91tn+₩287.0bn−₩142.9bn
Fri (08.28)−1.79%−₩852.5bn+₩419.4bn−₩1.21tn−₩22.9bn
Weekly total−1.79%−₩8.32tn+₩634.3bn+₩291.7bn−₩171.9bn

For the week, foreign investors sold a net -KRW 8,317.1bn, investment firms -KRW 312.1bn and pension funds -KRW 171.9bn, while retail investors bought +KRW 634.3bn.Foreign selling was front-loaded — most of the week’s total came on Monday at -KRW 3,669.1bn and Tuesday at -KRW 3,814.0bn, easing to -KRW 114.8bn on Wednesday and -KRW 852.5bn on Friday, with buying of +KRW 133.3bn on Thursday.Retail ran the other way — buying +KRW 3,321.7bn on Monday and +KRW 1,050.9bn on Tuesday, selling -KRW 2,246.1bn on Wednesday and -KRW 1,911.6bn on Thursday, then buying +KRW 419.4bn again on Friday.

Past patternCompressed to one line, the week reads as foreign investors selling early and retail absorbing early. But both groups reversed direction as the week went on.Flow figures shift with the moment and the route they are compiled through — Friday’s values here come from the 19:45 compilation via the fallback route, and the exchange’s own tally is confirmed on the next trading day, since exchange data collection is blocked.No direction for next week is built from a single flow line — this week already contained sessions where the index rose on days foreign investors sold heavily.
04 · Actor stocksWeekly totals · as of Friday (08.28) close

What each group bought and sold

A window on the stock each group bought most and sold most that week

Foreign investors bought Samsung Electro-Mechanics while retail sold it — same name, opposite sides

Top and bottom stocks by weekly net buying · in won · source: Korea Exchange
Investor groupBought mostSold most
Foreign investorsSamsung Electro-Mechanics+₩378.5bnSK hynix−₩5.42tn
Retail investorsSamsung Electronics+₩1.87tnSamsung Electro-Mechanics−₩550.3bn
Investment firmsSamsung Electro-Mechanics+₩199.7bnSamsung Electronics−₩689.3bn
Pension fundsSamsung SDI+₩146.8bnSamsung Electronics−₩282.7bn

Looking at what each group bought and sold, one name splits them squarely. Foreign investors bought the most of Samsung Electro-Mechanics at +KRW 374.9bn, while retail investors sold the most of that same name at -KRW 550.3bn.In the large semiconductor names it runs the other way — foreign investors sold SK hynix -KRW 5,420.8bn and Samsung Electronics -KRW 2,522.0bn, while retail bought Samsung Electronics +KRW 1,874.2bn, Samsung Electronics preferred +KRW 988.8bn and SK hynix +KRW 634.5bn.Pension funds bought Samsung SDI +KRW 146.8bn, NAVER +KRW 95.6bn and Doosan Enerbility +KRW 90.7bn while selling Samsung Electronics -KRW 282.7bn and Hyundai Mobis -KRW 145.6bn. Investment firms bought Samsung Electro-Mechanics +KRW 199.7bn and Doosan Enerbility +KRW 182.1bn while selling Samsung Electronics -KRW 689.3bn.These figures are compiled from a set of names tracked by turnover, not from every listed stock.

SampleSample: 70 tracked names by turnover — not a full-market total.
05 · Weekly eventsCollected from Yonhap RSS · five-layer classification

The week’s events

A window on what moved the market over the week and what followed, in order

Monday stacked regulatory and acquisition news; Thursday was the day Nvidia reported

Result = that day’s KOSPI change (no single-cause attribution — overlapping drivers move together)
DayLayerEventOutcome
MonPolicyDS Investment & Securities: “Samsung Electronics could retire KRW 10–20tn of treasury shares under the 10% financial holding rule”KOSPI −3.12%
MonIndustryHugging Face, the AI platform once breached via GPT, is up for sale at KRW 18tnKOSPI −3.12%
TueIndustryLarge firms excluding Samsung Electronics and SK hynix: operating profit up 72%, mid-to-long-term capex down 11%KOSPI +0.68%
TuePolicyTrump administration: “USD 140m fee on professional visas to generate KRW 12tn in revenue” (2nd roundup)KOSPI +0.68%
WedMacroCanada hits the US with USD 20bn in retaliatory tariffs — 15–50% on 700 itemsKOSPI +0.97%
WedIndustryNew York stocks close broadly higher on semiconductor strength and falling Treasury yieldsKOSPI +0.97%
ThuEarningsNvidia posts quarterly revenue of KRW 133tn, up 106% year on yearKOSPI +1.53%
ThuEarningsNvidia posts quarterly revenue of USD 96.2bn — a record for the 13th straight quarterKOSPI +1.53%
FriIndustrySamsung Biologics raises KRW 3tn in a rights offering for the Polypeptide acquisition and facility investmentKOSPI −1.79%
FriIndustrySK hynix breaks ground on its Indiana fab in the US — hundreds of thousands of wafers a year of 7th-generation HBM (2nd roundup)KOSPI −1.79%
Mon · Policy
EventDS Investment & Securities: “Samsung Electronics could retire KRW 10–20tn of treasury shares under the 10% financial holding rule”OutcomeKOSPI −3.12%
Mon · Industry structure
EventHugging Face, the AI platform once breached via GPT, is up for sale at KRW 18tnOutcomeKOSPI −3.12%
Tue · Industry
EventLarge firms excluding Samsung Electronics and SK hynix: operating profit up 72%, mid-to-long-term capex down 11%OutcomeKOSPI +0.68%
Tue · Policy
EventTrump administration: “USD 140m fee on professional visas to generate KRW 12tn in revenue” (2nd roundup)OutcomeKOSPI +0.68%
Wed · Macro
EventCanada hits the US with USD 20bn in retaliatory tariffs — 15–50% on 700 itemsOutcomeKOSPI +0.97%
Wed · Industry
EventNew York stocks close broadly higher on semiconductor strength and falling Treasury yieldsOutcomeKOSPI +0.97%
Thu · Earnings
EventNvidia posts quarterly revenue of KRW 133tn, up 106% year on yearOutcomeKOSPI +1.53%
Thu · Earnings
EventNvidia posts quarterly revenue of USD 96.2bn — a record for the 13th straight quarterOutcomeKOSPI +1.53%
Fri · Industry structure
EventSamsung Biologics raises KRW 3tn in a rights offering for the Polypeptide acquisition and facility investmentOutcomeKOSPI −1.79%
Fri · Industry structure
EventSK hynix breaks ground on its Indiana fab in the US — hundreds of thousands of wafers a year of 7th-generation HBM (2nd roundup)OutcomeKOSPI −1.79%
06 · Wall St. scoreboardStance vs. actual three trading days later · cumulative scoring

Wall Street scoreboard — weekly summary

A window grading, cumulatively, whether the stance of US investment bank reports matched reality three days later

Wall Street reports: 14 of 26 correct in the cumulative record — 54%

Silmari scores whether a name or index moved in line with an investment bank report’s stance three trading days after it was published.0 new foreign investment bank reports were detected this week — the sample is still building, so some weeks have none, and an empty week is not filled in.The cumulative record stands at 14 of 26 correct, or 54%. That is not far from a coin flip, and since the set was gathered retroactively it may carry collection bias.

InstitutionsReportActualVerdict
Bernstein (06.22)Samsung Electronics—Bernstein raises targets for Samsung, SK Hynix, Micron…”Rising memory prices ease AI cost pressures” (Positive)+1.41%
Nomura (06.24)Samsung Electronics—Nomura “590K→670K”…Samsung target raised again (Positive)−5.14%
JPMorgan (06.25)KOSPI—JPMorgan raises 12-month target to 12,500…”Maximize Korean equity weight” (Positive)−5.08%
Morgan Stanley (07.13)SK Hynix—Semiconductor overbought warning (memory winter precedent) (Negative)−0.16%
Barclays (07.23)SK Hynix—Target price $330 (117% upside) (Positive)−19.23%
CumulativeCumulative: 14 of 26 calls correct (54%) · no newly scored reports this week — showing the last 5 verdicts
07 · LessonsAs of Friday (08.28) close

The week’s lesson

A window for what to carry past the end of the week

What the week leaves — the weight of one day, two indices apart, flows that reversed

One day set the weekAfter -3.12% on Monday the index rose four sessions running, and the week still closed at -1.79%. Some weeks the four cannot cover the one.
The indices partedKOSPI -1.79% for the week against KOSDAQ +4.55%. Of the five sessions, the two closed the same way on only three.
No single causeMonday stacked a regulatory reading, a corporate sale and a product listing on the same day. None of them is written here as the cause.
Flows reverseForeign investors sold KRW 3,669.1bn and KRW 3,814.0bn on Monday and Tuesday, then bought KRW 133.3bn on Thursday. Retail switched twice as well — within a single week a group’s position is not fixed.
Same name, opposite sidesSamsung Electro-Mechanics was the name foreign investors bought most and the name retail sold most. Which side was right is not something this page says.

This was a week in which one large session set the record, the two indices looked in different directions, and flows by group reversed midweek.That makes it poor material for a one-line forecast of the week ahead — direction changed several times within this week alone. What to make of it is each reader’s own call.

Sources: Korea Exchange · FinanceDataReader · verified · as of Friday (08.28) close (confirmed) · The Silmari desk.
This edition organises and explains publicly available market data. It is not investment advice. Predictions and their scores are preserved without revision — the judgement is yours.