Today’s Verdict
KOSPI +0.88% on Samsung buyback; KOSDAQ −4.63% as defense and power sectors rout
The KOSPI closed Friday, August 21 (2026) at 6,912.95, up +0.88%, as Samsung Electronics’ announcement of a ₩15tn share buyback for employee compensation — disclosed after the close — gave a tailwind to the two largest names; after-hours, Samsung Electronics was indicated lower on Nextrade Alternative Trading SystemKorea’s alternative trading venue (ATS) launched in 2026, operating pre-market, main, and after-market sessions alongside the KRX main board.NXT intraday data — available with a 20-minute delay — provide an early signal of after-hours positioning; today’s NXT snapshot showed Samsung Electronics −0.55% and SK hynix +4.32% after the main-board close..The KOSDAQ told a different story, shedding −4.63% to close at 801.94, with defense, power, and biotech stocks hit hard and decliners outnumbering advancers by nearly five to one.
| Index | Close | Today | 1 week ago 08/14 | 1 month ago 07/22 | 1 quarter ago 05/22 | 6 months ago 02/20 | 1 year ago 08/21 |
|---|---|---|---|---|---|---|---|
| KOSPI | 6,912.95 | +0.88% | −0.93% | +1.70% | −11.91% | +19.01% | +120.04% |
| KOSDAQ | 801.94 | −4.63% | −7.25% | +6.77% | −30.93% | −30.51% | +3.18% |
Did our calls hold?
A window grading the morning’s calls against what actually happened
Morning call: KOSPI hit (P1 ✓), KOSDAQ missed badly (P2 ✗)
Two predictions were on the record for Friday, August 21 (2026): P1 called KOSPI +0.3% to +1.5% — the index settled at +0.88%, inside the band, verdict ✓.P2 called KOSDAQ flat (−0.5% to +0.5%); the index fell 4.63%, a miss of roughly four percentage points — verdict ✗.
No sector-level or individual-stock directional calls were filed for today; the two market-level calls covered the scope of the morning edition.
The day’s path
A window retracing where the index travelled from open to close
KOSPI charted a wide intraday range of 211.68 points (open 6,755.83, session low 6,742.44 at 09:01, session high 6,954.12 at 14:19) before closing at 6,912.95.
Who bought and who sold —4 investorgroups ×4periods
A window on how much foreign investors, retail investors, investment firms and pension funds each bought and sold
Institutions net-bought ₩248.1bn on KOSPI while retail sold ₩1,165.2bn — a split that mirrored the index’s Friday, August 21 (2026) close of +0.88%.
| Investor group | Today | 1 Week 08.14~08.21 | 1 Month 07.22~08.21 | Quarter |
|---|---|---|---|---|
| Foreign investors | −₩176.0bn | +₩1.19tn | +₩220.4bn | −₩65.80tn |
| Retail investors | −₩1.17tn | −₩40.8bn | −₩890.7bn | +₩50.95tn |
| Pension funds | +₩46.4bn | −₩103.6bn | +₩509.7bn | −₩2.45tn |
| Investment firms | +₩72.7bn | −₩3.82tn | −₩3.93tn | +₩14.45tn |
Institutions (aggregate) were the net buyers on the KOSPI today, taking in ₩248.1bn, led by investment trusts at ₩72.7bn and the National Pension Service at ₩46.4bn.Foreigners net-sold ₩176.0bn on the KOSPI spot market — a reversal from the one-week cumulative net purchase of ₩1,188.4bn, though on the futures market foreigners were net buyers of 1,125 contracts today, a divergence that in the 2026 regime has historically foreshadowed near-term positioning shifts.
Retail investors net-sold ₩1,165.2bn on KOSPI today — the fifth Friday in the 2026 regime when retail sold heavily against institutional buying.The 2026-regime lag data show a same-day correlation of −0.85 between foreign net buying and retail net buying (i.e., they characteristically trade opposite sides), a pattern that held today: foreigners sold spot while retail sold even harder, with institutions absorbing the flow.
The National Pension Service bought a net ₩46.4bn on KOSPI today, adding to a one-month cumulative purchase of ₩509.7bn — consistent with its pattern of counter-cyclical accumulation.Investment trusts (the largest sub-component of institutions) bought ₩72.7bn today but remain net sellers of ₩3,931.9bn over the past month, signaling that today’s buying is a partial offset within a longer withdrawal trend.
The KOSDAQ flow picture was the inverse of KOSPI: retail net-bought ₩623.6bn while foreigners net-sold ₩283.7bn and institutions net-sold ₩346.2bn — retail absorbed two-way selling from institutional and foreign participants.Over the past one month, foreigners have net-sold ₩1,643.3bn on KOSDAQ; retail has net-bought ₩1,554.6bn — the two flows have nearly offset each other while the index has struggled to hold the 800 level.
The quarter-to-date (May 21–August 21, 2026) picture is structural: foreigners have net-sold ₩65.80tn on KOSPI, offset by retail net-buying of ₩50.95tn and institutions of ₩11.02tn.On KOSDAQ, the quarter shows foreigners net-buying ₩354.5bn and investment trusts ₩1,378.1bn, while retail net-sold ₩927.9bn — a reversal of the KOSPI structure, suggesting different ownership dynamics between the two markets over a multi-month horizon.
Silmari Fear Gauge — past and present
A window measuring market anxiety through volatility, margin lending and short selling
The sentiment gauge held at 0.894 — “Neutral” stage — as leverage-ETF share and 20-day volatility remained among the most elevated inputs confirmed today.
The sentiment gauge scores 0.894 today, placing it in the “Neutral” stage (expanding-window percentile bands: Neutral = 35th–65th).Two inputs are confirmed as of today: 20-day volatility (Korea Volatility Index (proxy)A measure of implied 20-day realized volatility used in this edition as a proxy for the official VKOSPI, reflecting market uncertainty.At 5.97% today (93rd expanding-window percentile), the volatility input is among the more elevated confirmed readings in the sentiment composite and carries the highest weight (22.5%) in the gauge. proxy) at 5.97% sits at the 93rd expanding percentile; single-stock leverage-ETF share of total turnover at 2.845% sits at the 94th percentile — both among the more elevated confirmed readings in the composite.
Three inputs carry reporting lags: credit balance (T+1, last confirmed value 4.85 as of August 20), margin balance (T+1, last value 1.0 as of August 20), and short-surge (T+2, last value 4.73 as of August 18).The two remaining inputs — panic-buy-on-down-day and no-trigger streak — are scored zero today because the KOSPI closed up +0.88%, making them not applicable.
| Measure | Today’s value | Basis | Where today sits |
|---|---|---|---|
| Retail buying intensity on down days | 0.0 | Current regime (2026) percentile | 70(top 30%) |
| KOSPI 20-day realised volatility | 5.97 | Current regime (2026) percentile | 93(top 7%) |
| Consecutive no-trigger down days | 0.0 | Current regime (2026) percentile | 86(top 14%) |
| Leveraged-ETF share of turnover | 12.63 | Current regime (2026) percentile | 94(top 6%) |
Today is a trigger day for the KOSPI (+0.88%) but not for the KOSDAQ (−4.63%); the precursor score of 3 reflects signals that were set on prior sessions (ADR from July 28; short-surge from August 18) and remain active in the scoring window.The selling-acceleration signal (based on August 19–20 confirmed flows) is scored 0, meaning the confirmed data through those two sessions did not meet the threshold for that sub-signal.
On days when the sentiment gauge is in the Neutral stage without a confirmed trigger, the data do not support a directional conclusion from the gauge alone — the score reflects the cumulative weight of structural tensions (elevated leverage and volatility) rather than an acute selling event.The judgment is each reader’s own.
The gauge combines eight inputs, each weighted: 20-day realized volatility (weight 22.5%), single-stock leverage-ETF turnover share (10%), short-sale surge ratio (18%), credit balance five-day change (13.5%), margin balance level (18%), panic-buying on down-days (9%), no-trigger-streak count (9%), and a news-fear keyword proxy (excluded from the composite score but tracked separately at 13 keywords today) — all converted to expanding-window z-scores to prevent look-ahead bias.
The judgement is yours.
Short sellingSelling borrowed shares first, betting the price will fall.A rising balance means more money is betting on a decline.balance — the pattern of surges
A window on the stocks whose short balance rose or fell, and what happened afterwards
SK hynix’s short-sale position surged 5.0x on August 18 (2026); the current-regime base rate shows that in 120 similar events since 2026, the KOSPI averaged −0.15% five sessions later.
The most recent short-surge events in the data: SK hynix saw its short position rise 5.0x on August 18 (2026), triggering the surge definition (≥2.0x in five sessions, position ≥50,000 shares).In the current regime (2026–), the database records 120 similar surge events; the KOSPI’s average return five sessions later was −0.15%, with a down-day probability of 49% and an excess return versus the regime baseline of −2.82 percentage points — suggesting the surge carries a mild negative tilt in this regime, though the down-probability is near coin-flip.
Where the money moved —12sectors
A window on where money moved from and to, by sector
Defense & Aerospace fell −7.4% while Financials rose +1.4%, with Samsung Electronics (+3.87%) and SK hynix (+2.31%) keeping the semiconductor sector from a broader rout.
| Sector | Today | Flows | Relative (1w) | Leaders |
|---|---|---|---|---|
| Semiconductors | −1.95% | Buying | +3.60%p | Samsung Electronics+3.87%· SK hynix+2.31%· SK Square+0.00%· Samsung Electro-Mechanics−5.73%· Jusung Engineering−4.91% |
| AI & Software | −3.27% | Selling | −3.40%p | NAVER +1.14%· Kakao−7.49%· DearU−3.45% |
| Power & Electrical | −4.42% | Selling | −14.10%p | Doosan Enerbility−3.43% · LS ELECTRIC −6.12%· HD Hyundai Electric−3.75%· HYOSUNG Heavy Industries−4.76%· Gaon Cable−4.06% |
| Electronics & Components | −1.01% | Selling | −7.30%p | Samsung Electronics (Pref.)+8.26%· LG Energy Solution−4.05%· Samsung SDI−4.30%· LG Electronics−3.95% |
| Autos | −0.97% | Buying | −2.30%p | Hyundai Motor−0.60%· Kia−0.15%· Hyundai Mobis−2.17% |
| Defense & Aerospace | −7.40% | Buying | −9.90%p | Hanwha Aerospace−7.03%· LIG Defense & Aerospace−11.69%· Korea Aerospace Industries (KAI)−3.49% |
| Shipbuilding & Shipping | −2.10% | Buying | −8.60%p | Hanwha Ocean−4.86%· HD KSOE (Korea Shipbuilding & Offshore Engineering)−3.33% · HMM +1.89% |
| Financials | +1.40% | Buying | −3.70%p | KB Financial Group+2.69%· Shinhan Financial Group+2.97%· Hana Financial Group+4.38%· Mirae Asset Securities−4.43% |
| Bio & Healthcare | −3.07% | Selling | −2.30%p | Samsung Biologics−1.46%· Celltrion−0.93%· Alteogen−5.74%· Kolon TissueGene−4.16% |
| Construction & Infrastructure | −5.36% | Buying | −8.60%p | Hyundai E&C−7.21%· Daewoo E&C−4.67%· DL E&C−4.21% |
| Energy & Chemicals | −2.02% | — | −1.30%p | SK Innovation−0.87%· LG Chem−4.36% · S-Oil −1.05%· Lotte Chemical−1.81% |
| Consumer & Entertainment | −0.26% | Selling | −0.60%p | SK Telecom+5.80%· HYBE−3.17%· CJ CheilJedang−0.43% · JYP Ent. −3.24% |
The stocks that moved the market — top by turnover10
A window on which investor groups backed the most heavily traded stocks
Samsung Electronics (₩7.70tn) and SK hynix (₩7.43tn) together accounted for the majority of KOSPI turnover, reflecting a day of concentrated mega-cap activity.
Samsung Electronics (₩7.70tn turnover, +3.87%) and SK hynix (₩7.43tn, +2.31%) alone represented the top two slots on both turnover and absolute price contribution to the KOSPI — together they accounted for ₩15.13tn of the total ₩34.35tn market turnover, a KOSPI top-10 concentration of 71.4%.On KOSDAQ, Ingenium Therapeutics (Reg.S) led turnover at ₩415.3bn despite falling −13.97%, followed by Gido Industries at ₩213.4bn (−34.58%) — both names were among the session’s largest KOSDAQ decliners, consistent with a turnover-on-collapse pattern rather than momentum buying.
| Stock | Close | Change | Turnover | Foreign investors | Institutions | Investment firms | Pension funds | Retail investors |
|---|---|---|---|---|---|---|---|---|
| Samsung Electronics | ₩281,500 (≈$203.29) | +3.87% | ₩7.70tn | +₩439.4bn | +₩368.1bn | +₩243.7bn | +₩57.8bn | −₩743.3bn |
| SK hynix | ₩1,730,000 (≈$1,249.37) | +2.31% | ₩7.43tn | +₩14.4bn | +₩111.5bn | −₩12.2bn | +₩70.3bn | −₩1.26tn |
| Samsung Electronics (Pref.) | ₩207,000 (≈$149.49) | +8.26% | ₩2.17tn | −₩97.4bn | +₩181.0bn | +₩112.7bn | −₩7.8bn | −₩93.6bn |
| Samsung Electro-Mechanics | ₩1,316,000 (≈$950.39) | −5.73% | ₩928.8bn | −₩119.5bn | −₩117.0bn | −₩65.4bn | −₩31.5bn | +₩236.4bn |
| SK Square | ₩1,123,000 (≈$811.01) | +0.00% | ₩673.2bn | +₩2.9bn | +₩28.5bn | +₩4.7bn | +₩32.2bn | −₩29.4bn |
| Kumho E&C | ₩14,750 (≈$10.65) | −5.75% | ₩517.4bn | −₩9.9bn | +₩0.8bn | −₩0.2bn | +₩0.1bn | +₩7.6bn |
| Kakao | ₩35,800 (≈$25.85) | −7.49% | ₩353.4bn | −₩52.3bn | −₩45.3bn | −₩15.7bn | −₩5.7bn | +₩96.5bn |
| Samsung Life Insurance | ₩328,500 (≈$237.24) | +10.61% | ₩327.8bn | — | — | — | — | — |
| SK Securities | ₩2,955 (≈$2.13) | +5.16% | ₩273.3bn | — | — | — | — | — |
| Kumho Electric | ₩8,380 (≈$6.05) | +12.33% | ₩246.4bn | — | — | — | — | — |
Gainers5· Decliners5 — KOSPI & KOSDAQ
A window on the biggest gainers and decliners, and the reasons behind them
On the KOSPI, decliners outnumbered advancers 683 to 193 out of 942 issues even as the index closed up +0.88%, underscoring extreme concentration in a handful of large caps.
On the KOSPI, 683 issues fell versus 193 rising and 66 flat (ADR 0.28) even as the index closed up +0.88% — a high-concentration day where the top 10 stocks by turnover accounted for 71.4% of total KOSPI value traded.On the KOSDAQ, 1,378 issues fell versus 282 rising (ADR 0.20) — a breadth reading consistent with a broad-based down session; for comparison, the last available KOSDAQ breadth reading (August 19) showed ADR 0.31, so breadth weakened further today.
The SilmariDecouplingWhen two markets that used to move together break apart and move separately.The wider the gap, the less any single index can tell you about the market.Gauge
A window on the pattern in the KOSPI–KOSDAQ decoupling
The KOSDAQ closed at 801.94, down −4.63%, as decliners swamped advancers 1,378 to 282 with retail investors absorbing ₩623.6bn net.
The KOSDAQ’s −4.63% decline against the KOSPI’s +0.88% gain produced a spread of roughly 5.5 percentage points on the same session — a divergence driven by simultaneous net selling from foreigners (−₩283.7bn) and institutions (−₩346.2bn) on the smaller market, with retail the sole net buyer at +₩623.6bn.Over the past one month, KOSDAQ foreigners have net-sold ₩1,643.3bn while KOSPI foreigners were net buyers of ₩220.4bn — a structural preference for large-cap KOSPI names over KOSDAQ growth stocks that continued today.
Semiconductors → defensives, and back — by regime
A window on the pattern in sector rotation — money circulating from one sector to another
Defense & Aerospace shed −7.4% and Power & Electric −4.4% while Financials gained +1.4%, fitting the pattern of a sector rotation rather than a broad market sell-off.
| Regime | Reversion rate · sample |
|---|---|
| ① Old order (2018–24) | Average−0.84%· rose 45% of the time · 69 past cases |
| ② Transition (2025) | Average+1.70%· rose 71% of the time · 17 past cases |
| ③ Current regime (2026–) | Average+2.05%· Up 69% · 32 times previously |
A day when semiconductors (the average of SK hynix and Samsung Electronics) fall 2.0% or more while defensives (bio, food & beverage) outperform by 2.0%p or more = rotation (a flight)
The data define a rotation day as one where semiconductors (SK hynix + Samsung Electronics average) fall ≥2.0% AND a defensive cluster outperforms by ≥2.0 pp — that threshold was not fully met today: Samsung Electronics rose +3.87% and SK hynix +2.31%, keeping the semiconductor pair positive despite the sector aggregate falling −1.95%.Today is therefore not classified as a rotation event by the model definition; instead, it is characterized by selective mega-cap buying alongside broad defensive-sector and small-cap selling — a different configuration from a classic rotation signal.
The night makes the morning —American Depositary Receipt (ADR)A twin of a Korean stock, listed on a U.S. exchange.It prints overnight, showing how U.S. investors price Korean stocks before Seoul opens.crash detection
A window on how U.S.-listed Korean stocks moved overnight
The crash-precursor score stands at 3 out of a possible 4 active signals, driven by ADR and a short-surge flag, though two inputs remain on reporting lags.
The crash-precursor score stands at 3 out of 4 possible active signals: ADR (scored from the US session of July 28, 2026, −16.7%) and the short-surge flag (SK hynix 5.0x on August 18) are both active; selling-acceleration and the sentiment-90+ flag are both scored zero as of today’s confirmed data.A score of 3 is not a binary warning — the four signals were designed to be read in combination and in the context of the regime; the data do not provide a historical win-rate for a score of exactly 3 in the 2026 regime separately from the broader precursor table.
Tonight — the U.S. session about to open
S&P 500 and Nasdaq futures both pointed lower as of 05:00 KST — ES=F at 7,667.75 (−0.97%), NQ=F at 29,317.25 (−1.20%) — with rising Treasury yields the stated catalyst.
Korea–U.S. mutual following — overnight grading
A window on which market followed which
The SOX rose +0.53% on Thursday, August 20 (2026); Korea’s KOSPI followed in the same direction Friday, consistent with the 2026 YTD pattern in which Korea trailed the US in 39 of 139 measured sessions.
The SOX rose +0.53% on August 20 (2026); today’s KOSPI closed +0.88%, moving in the same direction — consistent with a Korea-follows-US signal for this session.In the 2026 YTD sample of 139 measured sessions, Korea followed the US in 39 sessions, the US followed Korea in 30, both moved together (bidirectional) in 46, and 24 showed no tracking — meaning same-direction movement occurred in a meaningful but not dominant share of sessions, and today’s alignment is one data point within that distribution.
The 2026 YTD cross-follow tally (Korea trailing US: 39, US trailing Korea: 30, bidirectional: 46) suggests neither market is a consistent one-way leader — the bidirectional category is the single largest bucket.Tonight, with US futures already pointing lower (ES=F −0.97%), the tracking question for Monday will be whether Korean markets open with a gap reflecting tonight’s US move — the 2026 regime data do not specify a probability for that outcome separately from the general follow-rate.
Overnight SOX ↔ same-day KOSPI in the same direction (|SOX| ≥ 0.5%) = Korea following · same-day KOSPI ↔ that night’s SOX in the same direction (|KOSPI| ≥ 0.5%) = the U.S. following
The won — the signal is the speed of the move, not its direction
A window on the pressure the won-dollar rate puts on foreign flows
The won traded at ₩1,384.7 per dollar as of the last available strip reading, with the DXY dollar index at 98.6 — down −0.29% on the day.
The won-dollar rate stood at ₩1,384.7 per dollar in the latest available strip reading; the DXY dollar index was at 98.6, down −0.29% on August 21 (2026).The yen-won cross (100 yen) was at ₩873.13; the Nikkei 225 closed at 66,016.36 (−0.31% on the day, per the confirmed strip reading), suggesting the yen did not strengthen enough to compress Korean export-sector margins materially on this session.
Rates — a weaker link than commonly assumed
A window on the burden rates and bonds place on equities
The US 10-year Treasury yield stood at 4.70% as of August 20 (2026), up +0.92% on the session, after the Treasury Secretary’s bond-buyback rally faded.
The US 10-year Treasury yield was at 4.70% as of August 20 (2026), up +0.92% on the session, after Treasury Secretary Bessent’s bond-buyback comments failed to sustain a rally in longer-dated bonds — per the event calendar headline from 18:36 KST.The overnight futures data (ES=F −0.97%) cited rising Treasury yields as the primary catalyst for equity weakness heading into the US Friday session; the August 21 (2026) Korean session preceded this US move, so the rate signal was not yet fully priced into Korean equities today.
Reference — brokerages, Wall Street and the windows
A window collecting brokerage research and overseas news
No brokerage reports were collected for today’s edition; Wall Street scorecard stands at 54% accuracy across 28 tracked calls.
No brokerage reports were collected for Friday, August 21 (2026): the data system retrieves only current reports from the NAVER Research portal, and same-day reports are not recoverable after the session unless captured in real time — none were captured today.
15 of 28 calls correct (54%) — measured three trading days after publication.
The Wall Street Scorecard tracks directional calls made by nine named brokerages over a three-session horizon; as of today the cumulative record stands at 15 hits out of 28 total calls, a 54% accuracy rate — Nomura leads at 4/6 and JP Morgan and Barclays are each 0/3 and 0/2 respectively.
The event calendar for today’s session carried 15 items across macro, industrial, geopolitical, and policy categories; key themes overlapping with this edition’s blocks include: Samsung Electronics’ ₩15tn employee share buyback (after close), Samsung SDI’s ₩4.4tn Samsung Display stake sale for investment funding (after close), US Treasury yield rebound as Bessent’s buyback rally faded (pre-market), and oil prices rising on US-Iran economic pressure comments.Because multiple macro and corporate events landed on the same session, this edition does not attribute the day’s moves to any single cause.
Detailed per-stock data (open, high, low, close, turnover) for all named companies in this edition are drawn from KRX same-day confirmed figures and NXT intraday snapshots (20-minute delay); NXT after-market data for August 21 (2026) will be confirmed in the following session’s data file.
Closing today, on to tomorrow
A window that closes today and hands over to tomorrow
The KOSPI call (P1: +0.88%, within the +0.3–+1.5% band) hit; the KOSDAQ call (P2: flat ±0.5%) missed badly — the index fell 4.63%, which the model attributed only to weak momentum, not to the broad-based institutional and foreign selling that materialized. The lesson: on days when both foreigners and institutions sell KOSDAQ simultaneously, a flat call is insufficient regardless of the SOX signal.