Today’s Verdict
Semiconductors Reignite KOSPI: Index Surges +3.68% to 6,579 on Foreign Buying
The KOSPI closed at 6,579.04 on Wednesday, August 12 (2026), rising +3.68% as foreign investors posted net KOSPI purchases of ₩2,835.4bn — their largest single-day buy in the current week — concentrated in Samsung Electronics (+6.68%) and SK hynix (+5.54%).Multiple inputs converged on the same day: the Philadelphia Semiconductor IndexA U.S. index tracking roughly 30 semiconductor design and manufacturing companies, widely used as a real-time proxy for global chip demand.Korean large-cap semiconductors move closely with the SOX; the 2026-regime same-day correlation to KOSPI is +0.511 per the data. had risen +0.87% the prior session, a Wednesday seasonal tailwind (80% up-rate in 2026, n=30), and AI-demand headlines all pointed in the same direction — the data does not isolate a single cause.
| Index | Close | Today | 1 week ago 08/05 | 1 month ago 07/13 | 1 quarter ago 05/13 | 6 months ago 02/11 | 1 year ago 08/12 |
|---|---|---|---|---|---|---|---|
| KOSPI | 6,579.04 | +3.68% | −0.29% | −3.35% | −16.13% | +22.87% | +106.25% |
| KOSDAQ | 858.91 | +0.12% | +7.42% | +7.45% | −27.02% | −22.96% | +6.41% |
Did our calls hold?
A window grading the morning’s calls against what actually happened
Morning calls went 1-for-5 outright: the KOSPI direction was correct but the magnitude was badly underestimated, costing four of five predictions their full marks.
Of five morning calls, one hit outright (P2: KOSDAQ +0.12% inside the −0.3–+0.5% band ✓), three were directionally correct but badly undershot on magnitude (P1 KOSPI +3.68% vs +0.5–+1.5% △; P3 Samsung +6.68% vs +1–+2% △; P4 SK hynix +5.54% vs +1.5–+2.5% △), and one missed entirely (P5: Jusung Engineering called −2–+2% but closed +7.14% ✗).The scorecard is 1 hit, 3 partial, 1 miss — the direction read was broadly right, but every magnitude band for the chip names was too conservative given the simultaneous alignment of SOX momentum, AI-demand headlines, and Wednesday seasonal strength.
No calls were placed on sectors or macro variables in this morning’s edition; the five predictions covered were the full set on record.
The day’s path
A window retracing where the index travelled from open to close
KOSPI opened at 6,438.5, hit a session low of 6,413.5 at 09:09, peaked at 6,668.43 at 12:19, then faded to close at 6,579.04 — a high-to-close retreat of roughly 89 points.
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
Foreign investors net bought ₩2.84tn on KOSPI Wednesday, August 12 (2026), driving the index up +3.68% to 6,579.04.
| Investor group | Today | 1 week 08.06~08.12 | 1 month 07.13~08.12 | Quarter |
|---|---|---|---|---|
| Foreign investors | +₩2.84tn | −₩2.76tn | −₩2.04tn | −₩92.88tn |
| Retail investors | −₩3.19tn | +₩1.24tn | +₩1.54tn | +₩74.25tn |
| Pension funds | −₩28.1bn | −₩285.1bn | +₩911.8bn | −₩3.10tn |
| Investment firms | +₩523.1bn | +₩1.63tn | −₩1.85tn | +₩21.88tn |
Foreign investors were the decisive engine on Wednesday, August 12 (2026), posting KOSPI net purchases of ₩2,835.4bn — reversing the prior one-week cumulative net sale of ₩2,756.3bn in a single session.The semiconductor sector absorbed the bulk of foreign capital: Samsung Electronics attracted ₩1,477.5bn and SK hynix ₩845.1bn in foreign net buying, together accounting for the majority of the day’s total foreign inflow.
Retail investors sold ₩3,191.1bn net on KOSPI — effectively the counterparty to foreign and institutional buying.In the 2026 regime, the same-day correlation between foreign net buying and the KOSPI return is +0.511 (lag 0), and retail flows run in the opposite direction (−0.846 correlation to foreign); today’s configuration was fully consistent with that structural pattern.
Investment trusts added ₩523.1bn net on KOSPI, while the broader institutional aggregate contributed ₩527.9bn.The National Pension Service was a modest net seller at −₩28.1bn on KOSPI and −₩18.8bn on KOSDAQ — a counter-cyclical trim consistent with its rebalancing mandate after consecutive days of gains.
KOSDAQ flows were structurally weaker: foreign investors net sold ₩162.3bn, investment trusts net sold ₩88.0bn, and only retail stepped in (+₩312.7bn), a configuration that matches KOSDAQ’s +0.12% close versus KOSPI’s +3.68%.The KOSPI-KOSDAQ gap of 3.56 percentage points reflects concentrated foreign demand for large-cap chip names rather than any broad risk-on extension into smaller stocks.
Over the current quarter (May 13 – August 12, 2026), foreign investors have net sold ₩92,875.7bn on KOSPI while retail investors have accumulated +₩74,248.8bn — a structural divergence of more than ₩90tn that today’s single-session reversal does not yet offset.Investment trusts are the only institutional cohort with meaningful positive quarterly accumulation (+₩21,875.5bn on KOSPI), suggesting pension and insurance demand rather than active fund conviction has been the backstop.
Silmari Fear Gauge — past and present
A window measuring market anxiety through volatility, margin lending and short selling
The sentiment gauge held at 0.86 — rated Neutral — even as volatility (vol20: 6.16, 95th percentile) remained the dominant input.
Today’s sentiment gauge scored 0.86, placing it in the Neutral stage (scores below the 65th expanding percentile threshold).The dominant readable input was vol20 at 6.16 — the 95th percentile of the expanding sample — while leverage ETF share sat at 10.7% (82nd percentile), the no-trigger streak contributed at the 85th percentile, and the panic-buy-on-dip sub-signal (pbuy_down) registered at the 70th percentile.
Credit balance (credit5d), margin loan data, and short-surge data were not collected for today’s computation and are excluded from the score — the gauge is therefore running on four of eight inputs.The Neutral stage in the 2026 regime does not itself carry a directional base rate in the data provided; no forward-return table for this stage is available to cite.
| 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 | 6.16 | Current regime (2026) percentile | 95(top 5%) |
| Consecutive no-trigger down days | 0.0 | Current regime (2026) percentile | 85(top 15%) |
| Leveraged-ETF share of turnover | 10.7 | Current regime (2026) percentile | 82(top 18%) |
No score-trigger event was active today: the crash-precursor total was 2, with only the ADR sub-signal contributing (scored from the most recent available U.S. session ADR reading of −16.7% dated July 28, 2026).Short-surge, accelerating-sell, and sentiment-90+ sub-signals all registered zero.
On days when the sentiment gauge sits in Neutral and no trigger fires, the gauge is designed to record the ambient temperature rather than issue an alert — today is one such day.The +3.68% KOSPI move was driven by externally visible inputs (SOX, AI headlines, Wednesday seasonality) rather than by a shift in the internal gauge, which underlines the gauge’s role as a risk monitor rather than a return predictor.
The eight components of the sentiment gauge are: ① credit balance 5-day change (weight 13.5%), ② margin loan balance (18%), ③ panic-buying-on-dip ratio (9%), ④ short-selling surge count (18%), ⑤ 20-day realized volatility (22.5%), ⑥ consecutive no-trigger streak (9%), ⑦ leverage ETF share of total turnover (10%), and ⑧ a news fear-keyword proxy (referenced for reporting but excluded from the composite score due to archive limitations). The judgment is each reader’s own.
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
No new short-selling surge events were flagged for Wednesday, August 12 (2026); the most recent cluster dates to August 4–6.
The most recent short-selling surge events on record occurred between August 4–6, 2026, affecting Kumho Construction (×2.7, surge date Aug 5), Simtec (×4.0, Aug 5), Samsung Electronics preferred (×2.2 and ×3.1), LG Innotek (×4.4), and Eugene Tech (×2.1).In the 2026 regime (n=102 surge events), the five-day average return after a surge is −1.1% with a 52% probability of a down outcome — the excess return versus the regime baseline of +2.96% is −4.06pp, making post-surge periods a meaningfully weaker window than non-surge days in the current environment.
Where the money moved —12sectors
A window on where money moved from and to, by sector
Semiconductors (+5.18%) and electronics/components (+5.72%) led the advance; AI/software (−0.79%) and shipbuilding/shipping (−1.52%) lagged.
| Sector | Today | Flows | Relative (1w) | Leaders |
|---|---|---|---|---|
| Semiconductors | +5.18% | Buying | +4.20%p | Samsung Electronics+6.68%· SK hynix+5.54%· SK Square+8.36%· Samsung Electro-Mechanics+5.78%· Jusung Engineering+7.14% |
| AI & Software | −0.79% | Selling | −5.60%p | NAVER +0.70%· Kakao−2.83%· DearU−0.25% |
| Power & Electrical | +3.36% | Buying | −1.40%p | Doosan Enerbility+3.08% · LS ELECTRIC +2.71%· HD Hyundai Electric+5.82%· HYOSUNG Heavy Industries+2.15%· Gaon Cable+3.05% |
| Electronics & Components | +5.72% | Buying | +14.50%p | Samsung Electronics (Pref.)+3.27%· LG Energy Solution+1.13%· Samsung SDI+5.66%· LG Electronics+12.82% |
| Autos | +1.06% | Buying | +1.50%p | Hyundai Motor+1.61%· Kia+0.97%· Hyundai Mobis+0.61% |
| Defense & Aerospace | +5.10% | Selling | +15.10%p | Hanwha Aerospace+5.28%· LIG Defense & Aerospace+3.68%· Korea Aerospace Industries (KAI)+6.35% |
| Shipbuilding & Shipping | −1.52% | Buying | −1.70%p | Hanwha Ocean+1.24%· HD KSOE (Korea Shipbuilding & Offshore Engineering)−4.40% · HMM −1.39% |
| Financials | +0.49% | Buying | −2.50%p | KB Financial Group−0.36%· Shinhan Financial Group−0.67%· Hana Financial Group+0.16%· Mirae Asset Securities+2.82% |
| Bio & Healthcare | −0.50% | Buying | +4.20%p | Samsung Biologics−3.73%· Celltrion−4.04%· Alteogen−3.05%· Kolon TissueGene+8.82% |
| Construction & Infrastructure | +1.75% | Selling | +3.70%p | Hyundai E&C+1.34%· Daewoo E&C+2.94%· DL E&C+0.96% |
| Energy & Chemicals | −0.31% | — | +15.80%p | SK Innovation−1.37%· LG Chem+0.55% · S-Oil −0.07%· Lotte Chemical−0.34% |
| Consumer & Entertainment | −0.03% | Selling | −5.10%p | SK Telecom+2.09%· HYBE−0.44%· CJ CheilJedang−0.59% · JYP Ent. −1.18% |
The stocks that moved the market — top by turnover10
A window on which investor groups backed the most heavily traded stocks
Samsung Electronics (₩6,868.9bn) and SK hynix (₩6,828.2bn) together dominated KOSPI turnover, each gaining more than 5%.
Samsung Electronics (₩6,868.9bn) and SK hynix (₩6,828.2bn) together represented roughly 40% of all KOSPI turnover on Wednesday, August 12 (2026), with Samsung Electro-Mechanics (₩925.9bn) and SK Square (₩721.5bn) rounding out the semiconductor complex in the top five.On the KOSDAQ side, Jusung Engineering led with ₩452.2bn — more than double the second-ranked name — reflecting continued semiconductor-equipment demand expectations despite having already surged +12.15% the prior day.
| Stock | Close | Change | Turnover | Foreign investors | Institutions | Investment firms | Pension funds | Retail investors |
|---|---|---|---|---|---|---|---|---|
| Samsung Electronics | ₩255,500 | +6.68% | ₩6.87tn | +₩1.48tn | +₩196.3bn | +₩291.6bn | −₩31.9bn | −₩1.53tn |
| SK hynix | ₩1,504,000 | +5.54% | ₩6.83tn | +₩852.2bn | +₩288.8bn | +₩176.7bn | +₩43.6bn | −₩1.14tn |
| Samsung Electro-Mechanics | ₩1,335,000 | +5.78% | ₩925.9bn | +₩175.9bn | +₩108.5bn | +₩50.3bn | +₩9.2bn | −₩274.8bn |
| SK Square | ₩1,024,000 | +8.36% | ₩721.5bn | +₩100.8bn | +₩59.3bn | +₩48.5bn | +₩3.8bn | −₩154.8bn |
| LG Electronics | ₩205,000 | +12.82% | ₩622.8bn | +₩115.3bn | +₩68.9bn | +₩32.8bn | +₩25.6bn | −₩183.3bn |
| Samsung Electronics (Pref.) | ₩186,100 | +3.27% | ₩588.9bn | −₩51.9bn | +₩23.1bn | +₩17.4bn | +₩21.3bn | +₩26.1bn |
| Daewon Cable | ₩16,030 | +10.40% | ₩432.6bn | +₩15.2bn | +₩9.5bn | +₩0.1bn | +₩0.2bn | −₩25.0bn |
| Hanwha Aerospace | ₩1,156,000 | +5.28% | ₩348.9bn | −₩19.3bn | +₩12.0bn | −₩6.8bn | +₩13.0bn | +₩4.4bn |
| Korea Kolmar | ₩132,500 | +22.80% | ₩329.4bn | −₩32.1bn | +₩25.4bn | −₩14.6bn | −₩9.7bn | +₩6.9bn |
| Kumho E&C | ₩14,930 | +29.94% | ₩293.5bn | +₩1.9bn | +₩0.7bn | −₩0.2bn | +₩0.0bn | −₩2.6bn |
Gainers5· Decliners5 — KOSPI & KOSDAQ
A window on the biggest gainers and decliners, and the reasons behind them
KOSPI breadth was net negative — 477 decliners against 380 advancers — even as the index closed up +3.68%, underscoring heavy-cap concentration.
The KOSPI advance ratio was inverted relative to the price move: 380 stocks rose, 477 fell, and 85 were flat — an ADR of 0.80, the weakest reading of the past five sessions.The top-10 turnover concentration of 66.3% confirms the gain was concentrated in a handful of large-cap names; KOSDAQ breadth was better at 886 up vs 753 down (ADR 1.18), though the index barely moved.
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
KOSDAQ closed up +0.12% at 858.91, trailing KOSPI by 3.56 percentage points as retail investors were the sole net buyers.
KOSDAQ closed at 858.91, up just +0.12% while KOSPI rallied +3.68% — a 3.56pp gap that reflects the chip-heavy weighting of KOSPI large-caps and the absence of broad risk appetite extending into smaller names.Foreign investors net sold ₩162.3bn on KOSDAQ today and have sold a cumulative ₩2,167.7bn over the past month, while retail has bought ₩889.7bn over the same window — a structural mismatch that has kept the junior market effectively range-bound.
Semiconductors → defensives, and back — by regime
A window on the pattern in sector rotation — money circulating from one sector to another
Today did not meet the defensive-rotation definition; semiconductors outpaced the tape sharply, with no broad defensive bid emerging.
| 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+1.92%· Up 70% · Past 30 occurrences |
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)
Today does not qualify as a defensive rotation day under the data’s definition (semiconductor average ≥−2% decline plus defensives outperforming by ≥2pp): the semiconductor sector gained +5.18% and was the session’s leading cohort.For reference, in the 2026 regime (n=30 rotation events), the three-day average return after a confirmed defensive-rotation day is +1.92% with a 70% up-probability — but that base rate does not apply here.
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 printed 2 out of a possible maximum, with only the ADR sub-signal active — no alarm threshold was breached.
The crash-precursor score today is 2/maximum, with only the ADR input active — drawn from the U.S. session ADR of −16.7% recorded on July 28, 2026, the most recent available data point.The short-surge input uses residual stock data lagged by T+2 publication; the accelerating-sell input is sourced from the August 10–11 confirmed flow data; and the sentiment-90+ threshold was not breached as of August 11 — all three sub-signals therefore contribute zero to today’s score.
Tonight — the U.S. session about to open
S&P 500 futures pointed to a mild pullback heading into Wednesday’s New York session, with ES down −0.28% and NQ down −0.36% as of 05:00 KST.
Korea–U.S. mutual following — overnight grading
A window on which market followed which
The SOX rose +0.87% on August 11 (2026); KOSPI followed with a +3.68% gain on August 12 (2026), a directional match consistent with the Korea-follows-US pattern.
The SOX closed +0.87% on August 11 (2026), clearing the ≥0.5% threshold used in the Korea-follows-US framework; KOSPI responded with a +3.68% advance on August 12 (2026), a directional match.The Nikkei 225 also confirmed: it rose +0.86% to 67,547.81 on August 12 (JST close), suggesting the day’s move had regional breadth rather than being Korea-specific.
In 2026 year-to-date (n=139 sessions), Korea-follows-US occurred 39 times, US-follows-Korea 30 times, bidirectional follow 46 times, and no follow 24 times.Today adds to the Korea-follows-US count; the bidirectional category (46 sessions) remains the modal outcome, suggesting neither market consistently leads the other in the current regime.
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 1,416.48 per dollar (−0.06%) on August 12 (2026), steady as the dollar index held near 99.84.
The won was quoted at 1,416.48 per dollar on August 12 (2026), a marginal −0.06% move, while the dollar index (DXY) held at 99.84 (+0.02%).The yen-to-won cross stood at 8.87; a stable won on a strong KOSPI day is consistent with foreign equity inflows partly offsetting any dollar demand from risk hedging.
Rates — a weaker link than commonly assumed
A window on the burden rates and bonds place on equities
The 10-year U.S. Treasury yield stood at 4.68% as of August 11 (2026), down 0.32% from the prior reading.
The 10-year U.S. Treasury yield was 4.68% as of August 11 (2026), down 0.32% from the prior reading — a modest easing that would ordinarily support risk assets, though the same-day data for August 12 has not yet been collected.Gold stood at $4,476.2/oz and copper at $6.69/lb as of the most recent strip readings, reflecting continued commodity firmness alongside equity gains.
Reference — brokerages, Wall Street and the windows
A window collecting brokerage research and overseas news
No brokerage reports were published today — the NAVER Research archive does not retain same-day reports once the session closes without prior collection.
No brokerage reports were collected for Wednesday, August 12 (2026). The NAVER Research portal retains only current reports; same-day coverage requires real-time collection that was not performed for this edition.
15 of 28 calls correct (54%) — measured three trading days after publication.
The Wall Street Scoreboard tracks directional calls from nine international brokerages across a rolling 3-session horizon; a call is scored correct if price moves in the stated direction within three sessions of publication. The current cumulative record across 28 tracked calls is 15 hits (54% accuracy), with Nomura leading at 4/6 and JP Morgan and Barclays each at 0 from 3 and 2 respectively.
Yonhap’s economic wire headline for today — “Semiconductors Regain Momentum; KOSPI Up 3.68% for Third Consecutive Gain” — overlaps directly with this edition’s lead. Additionally noted: a report that investor deposit balances fell below ₩100tn while margin credit held at ₩30tn, and domestic policy signals around AI infrastructure and a proposed semiconductor industrial site in the Honam region.
For individual company fundamentals (EPS, PER consensus), FnGuide provides only current-day values; historical consensus figures for August 12 (2026) cannot be retroactively retrieved.
Closing today, on to tomorrow
A window that closes today and hands over to tomorrow
The session delivered a sharp lesson in magnitude asymmetry: the morning edition called KOSPI up +0.5–+1.5% and Samsung Electronics up +1–+2%, but both closed at multiples of those bands (+3.68% and +6.68% respectively). When the SOX, AI-demand signals, and a Wednesday seasonal skew all align simultaneously, the historical regime average (+1.14%, 80% up-rate in 2026 Wednesdays, n=30) proved a floor, not a ceiling — and forecasts anchored to prior-day momentum rather than the confluence of factors missed the full move.