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Samsung Electronics +4.13% Leads; Defense Names Retreat — Wednesday Opens With Mixed Signals — Korea Market Pre-Open, Aug 12, 2026

Tuesday, August 11 (2026) closed with Samsung Electronics up 4.13% to ₩239,500 and SK hynix edging 0.35% higher to ₩1,425,000, while the defense and shipbuilding cluster — Korea Aerospace Industries, Hanwha Ocean, Hyundai Rotem, Hanwha Systems — gave back between 5.57% and 12.07%.Wednesday’s open ar

The Silmari
A daily data newsletter on the Korean stock market — silmari, ‘a clue: the loose end that unravels the knot’
① Pre-Open 07:302026.08.12 Wed · No. 10Crash-precursor score 3/10 — ADR and selling-acceleration sub-signals live; short-surge and sentiment-90+ at zero (data through Aug 11, 2026).
① Pre-Open · published 07:30 KST · before the open
01 · VerdictRegular session confirmed 15:30 KST

Today’s Calls

Samsung Electronics +4.13% Leads; Defense Names Retreat — Wednesday Opens With Mixed Signals

Tuesday, August 11 (2026) closed with Samsung Electronics up 4.13% to ₩239,500 and SK hynix edging 0.35% higher to ₩1,425,000, while the defense and shipbuilding cluster — Korea Aerospace Industries, Hanwha Ocean, Hyundai Rotem, Hanwha Systems — gave back between 5.57% and 12.07%.Wednesday’s open arrives with overnight US equity futures slightly negative (S&P 500 futures 0.28%, Nasdaq 100 futures 0.36%), while Nikkei CME futures added 0.49%; Japan’s cash market was closed Monday for Mountain Day.

Key points
01Samsung Electronics closed Tuesday at ₩239,500 (+4.13%) on ₩5,510.9bn turnover — the day’s heaviest KOSPI volume — while preferred shares rose 4.77%.
02Defense and shipbuilding names led declines: Korea Aerospace Industries 12.07%, LIG Defence & Aerospace 7.65%, Hanwha Ocean 5.72%, Hyundai Rotem 5.86%.
03The crash-precursor score stands at 3 (Advance-Decline Ratio (ADR)The ratio of advancing stocks to declining stocks in a market on a given day; a reading well above 1.0 indicates broad participation in a rally, well below 1.0 indicates broad weakness.An extreme ADR reading — especially a sharply negative US-session ADR — is one of the four sub-signals feeding the crash-precursor score used in this letter. sub-signal: 2; selling-acceleration sub-signal: 1; short-surge and sentiment-90+ sub-signals: 0 each) — elevated but below the alert threshold in the data.
04Wednesday seasonality (2026 regime, n=29): average change +1.05%, up-probability 79% — the strongest average of any weekday in this regime, though overnight futures are mildly negative.
02 · Prediction5 calls · posted 07:30 KST

Today’s Calls

Where the day’s calls are placed by number — grading starts with the Early Session edition

Today’s five calls — KOSPI +0.5–1.5%, Samsung Electronics +1–2%

Five calls go on the record at 07:30 KST today — KOSPI higher +0.5–1.5% (P1), KOSDAQ flat −0.3 to +0.5% (P2), Samsung Electronics +1–2% (P3), SK hynix +1.5–2.5% (P4), and Jusung Engineering flat-to-lower −2 to +2% (P5).Scoring begins with the Morning Session edition (10:00 KST) once the market opens; final verdicts run in tonight’s Final edition. We do not grade before the open.Yesterday (August 11) finished 0 hits, 1 partial and 4 misses: the KOSPI closed +0.73% against a call for a decline (✗), the KOSDAQ +0.39% earned partial credit (△), and SK hynix +0.35%, Hanwha Aerospace −4.69% and Alteogen −5.89% all missed.

calls placed today
5
posted 07:30 KST
Direction grading
from the 10:00 Early Session edition
Magnitude grading
settled in the 20:00 Final Edition
Call ① KOSPIThe KOSPI is more likely to rise
Band +0.5~+1.5% · full day
Morning rationalePhiladelphia Semiconductor Index (SOX)A US index tracking 30 companies involved in semiconductor design, manufacture, and distribution, widely used as a barometer for global chip-sector sentiment.Because Korean chip giants (Samsung Electronics, SK hynix) move in close correlation with SOX on many sessions, it is a primary overnight leading indicator for the KOSPI tech complex.+0.87% current conditions rally probability 85% (n=27)·expect day 2 of foreign inflow turnaround·AI boom reconfirmed (CoreWeave earnings surprise)·entering strong zone mid-month
Call ② KOSDAQKOSDAQ is more likely to finish flat
Band -0.3~+0.5% · full day
Morning rationaleYesterday KOSDAQ foreigners -3.6B₩·institutions -1B₩·individuals only +4.4B₩ small-cap net buys = low-reliability structure·expect SOX-driven KOSPI large-caps focus·options expiry D-1 volatility watch
Forecast ③ Samsung Electronics (005930·KOSPI)Samsung Electronics (005930·KOSPI) high probability of rally
Range +1~+2%·morning strength·afternoon profit-taking mixed
Morning rationaleSOX-linked current conditions average +1.76% (n=27)·after yesterday’s +4.13% surge must confirm trend continuation morning·refrain from gap-chasing buys
Forecast ④ SK Hynix (000660·KOSPI)SK Hynix (000660·KOSPI) high probability of rally
Band +1.5~+2.5% · morning
Morning rationaleSOX-linked current conditions average +2.00% (n=27)·CoreWeave AI data-center strong results =High-Bandwidth Memory (HBM)A stacked DRAM architecture that delivers very high memory bandwidth in a small footprint, currently the primary memory type used in AI accelerator chips.SK hynix is the leading HBM supplier; AI data-center earnings (such as CoreWeave) that signal strong HBM demand directly affect expectations for SK hynix revenue.(high-performance AI memory) demand direct signal·approach dip splits during session over gap-chasing rallies
Forecast ⑤ Juseong Engineering (036930·KOSDAQ)Juseong Engineering (036930·KOSDAQ) likely to trade flat to lower
Band -2~+2% · full day
Morning rationaleYesterday +12.15% single-day surge followed by next-day reversal pattern (orders·theme surge stocks often see profit-taking next day)·ban gap-up chasing buys·judge momentum continuation by whether close holds +6% or above

No brokerage reports were published in today’s data feed; the single-name calls above relied solely on quantitative regime statistics and prior-day momentum patterns.

03 · OvernightOvernight, confirmed abroad

The world overnight — how the US session ended

A window on what happened in the US market overnight

SOX +0.87%, S&P 500 −0.32%, Nasdaq −0.60% on August 11 — Chips Diverge From Broad Market

iShares MSCI South Korea ETF (EWY)A US-listed exchange-traded fund that tracks the MSCI Korea Index, denominated in dollars, giving foreign investors direct exposure to Korean equities.EWY’s daily move reflects dollar-based foreign demand for Korean stocks and often anticipates the next day’s KOSPI open when it diverges from the won-denominated close.(Korea ETF)167.24 (+2.53%· as of 2026-08-11)
Nikkei 22566970.22 (+2.08%· as of 2026-08-10)
Dollar index99.81 (+0.00%· as of 2026-08-11)
U.S. 10-year Treasury4.68 (−0.32%· as of 2026-08-11)
KRW/USD1412.44 (+0.39%· as of 2026-08-11)
Nasdaq26445.45 (−0.60%· as of 2026-08-11)
SOX semiconductors12098.47 (+0.87%· as of 2026-08-11)
S&P5007728.2 (−0.32%· as of 2026-08-11)

On August 11 (2026), the S&P 500 closed at 7,728.20 (−0.32%), the Nasdaq at 26,445.45 (−0.60%), and the SOX semiconductor index at 12,098.47 (+0.87%).The Wall Street directional scoreboard stands at 15/28 (54% hit rate, 3-day horizon) across nine broker desks; in the 2026 YTD sample, Korean equities followed a positive SOX print with a KOSPI gain in approximately 39 of 139 total sessions where either market led, though the categories overlap — direct SOX→KOSPI next-day probability is not separately tabulated in the available data.

04 · Cross-followingMeasured in 2026

Korea–U.S. mutual following — overnight grading

A window on which market followed which

SOX Rose 0.87% on Aug 11 — In 2026 YTD, Korean Equities Followed US Chips in 39 of 139 Sessions

The SOX Philadelphia Semiconductor Index rose 0.87% on August 11 (2026), while overnight S&P 500 futures are −0.28% and Nasdaq 100 futures are −0.36% as of 05:00 KST on August 12.In the 2026 YTD sample of 139 sessions, Korean equities followed the US direction in 39 cases, US markets followed Korea in 30, both moved together in 46, and neither tracked the other in 24.

The accumulated 2026 data show Korea-follows-US occurring in roughly 28% of sessions (39/139), meaning a positive SOX print does not mechanically translate into a KOSPI gain on the following day.With overnight US index futures mildly negative and the SOX reading positive, the cross-signal is mixed — historical split-signal sessions in this regime do not cluster toward either outcome in the available data.

Days Korea followed the U.S.39 days
Days the U.S. followed Korea30 days
Both ways46 days
Sample139 days

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

05 · Night windowOvernight indicators

Night window —EWYofficial indicator

A window on what overnight futures foreshadow for the next day’s open

S&P 500 Futures −0.28%, Nasdaq 100 Futures −0.36%, Nikkei CME +0.49% at 05:00 KST

EWY (Korea ETF)167.24 (+2.53%· as of 2026-08-11)
Nikkei 22566970.22 (+2.08%· as of 2026-08-10)
Dollar index99.81 (+0.00%· as of 2026-08-11)

As of 05:00 KST on Wednesday, August 12 (2026), overnight US and Nikkei futures show: S&P 500 futures (ES) −0.28% at 7,753.25, Nasdaq 100 futures (NQ) −0.36% at 29,646.75, and Nikkei CME futures (yen-denominated) +0.49% at 67,195 — these are CME-linked proxies, not the Korea 200 night futures, and carry up to ±1 hour timing approximation.The mixed signal (broad US futures negative, chip-adjacent Nikkei futures positive) does not have a clean historical precedent in the tabulated cross-follow data; in the 2026 YTD, split-signal sessions (Korea following US in 39 of 139) show no dominant directional outcome recorded in the available data.

06 · Pre-openPre-open check

Pre-open08:00~09:00single-price auction (open/close)The single-price auction window (before the open and just before the close), where orders are pooled and matched at once.When large volume crowds into this window, a gap is created.forecast

A window on where the pre-open auction is pulling the opening price

Nikkei CME Futures +0.49% vs. S&P 500 Futures −0.28% — Chip vs. Broad Split Heads Into Wednesday Auction

When the simultaneous-bid auction opens at 08:30 KST, the gap direction will be shaped by the overnight split: Nikkei CME futures +0.49% pulling against S&P 500 futures −0.28% and Nasdaq 100 futures −0.36% — watch whether the chip complex (Samsung Electronics, SK hynix) opens in line with the positive SOX or tracks the softer broad-index futures.Defense and shipbuilding names fell sharply on Tuesday; whether that sector’s selling has exhausted itself or continues will be a secondary auction signal — prior rotation episodes in the 2026 regime showed a 3-day recovery rate of 70% (n=30), but Tuesday’s move does not match the rotation definition in the data exactly.

KOSPIClose6,345.53· same-day+0.73%
KOSDAQClose857.84· same-day+0.39%
Historical contextWednesday 2026-regime seasonality (n=29): average KOSPI change +1.05%, up-probability 79%, average intraday range 4.15% — the highest average-change weekday in the current regime.
07 · ReviewConfirmed, previous session

Previous-Day Review

A window that retraces what happened in the previous session

Samsung Electronics +4.13%, Korea Aerospace −12.07%: Tech Bid, Defense Sold on Tuesday

KOSPIClose6,345.53· same-day+0.73%
KOSDAQClose857.84· same-day+0.39%
08 · Fear gaugeStanding gaugeAs of 08.11 — latest available gauge

The Silmari Fear Gauge

A window measuring market anxiety through volatility, margin lending and short selling

Crash-Precursor Score Holds at 3 — ADR Signal Still Live, Short-Surge Counter at Zero

Volatility percentile
95
0-100 · higher = louder warning · current-regime (2026) basis · as of 08.11 (previous trading day — today’s reading lands after the close)

The composite crash-precursor score is 3 as of the August 11 (2026) close, driven by an ADR sub-signal of 2 (reference: US session ADR −16.7% as of July 28) and a selling-acceleration sub-signal of 1 (based on confirmed flow data through August 10).The short-surge sub-signal registers 0 (short positions current to August 10 on a T+2 disclosure basis), and the sentiment-90+ sub-signal is also 0 (gauge reading through August 11).

In the 2026 regime (current phase), short-surge events were followed five days later by an average KOSPI return of −1.76% across 99 cases, with a down-probability of 54% — against a regime baseline of +2.98%, implying an excess of −4.74 percentage points.In the 2025 transition period (111 cases), the same event averaged +1.35% with a 45% down-probability; in the 2018–2024 regime (150 cases), −0.11% with a 57% down-probability.

Today (Wednesday, August 12, 2026) carries no independently flagged trigger in the collected data — the elevated ADR sub-signal and selling-acceleration sub-signal remain live from prior sessions, but no new short-surge or sentiment-90+ trigger has been recorded. The judgment is each reader’s own.

09 · FX windowFX window · reference time to be set

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

Won Quoted at 1,412.44 per Dollar on Aug 11, Up 0.39% on the Day

USD/KRW (Aug 11)1,412.44 (+0.39%)
US Dollar Index (DXY)A geometrically-weighted index measuring the dollar against a basket of six major currencies (euro, yen, pound, Canadian dollar, Swedish krona, Swiss franc).A rising DXY tends to strengthen the won’s relative weakness, raising the USD/KRW rate and affecting the returns foreign investors see when they hold Korean assets. Dollar Index99.81 (flat)
JPY/KRW (cumulative strip)8.85
US 10-yr Treasury4.68% (0.32% on Aug 11)
EWY Korea ETF (Aug 11)167.24 (+2.53%)

The won was quoted at 1,412.44 per dollar on August 11 (2026), up 0.39% on the day, while the dollar index (DXY) stood at 99.81, flat on the day.A won at this level (~1,412) represents a modest headwind for import-cost-sensitive names and a tailwind for exporters, though the EWY Korea ETF — a proxy for foreign investor appetite — rose 2.53% on August 11, suggesting dollar-denominated demand for Korean equities remained positive on that session.

10 · KOSDAQ windowKOSDAQ data sourced from Naver Finance fallback; KOSDAQ investor-flow breakdown (today / 1-week / 1-month / quarter) is unavailable — Naver fallback covers KOSPI only.

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

Jusung Engineering +12.15% Led KOSDAQ Volume at ₩519.0bn; Alteogen Shed 5.89% on ₩245.4bn Turnover

KOSPI · KOSDAQ close6,345.53 · 857.84
Today’s change+0.73% · +0.39%
Today’s gap (KOSPI − KOSDAQ)+0.33%p— below the 2pp promotion threshold
Year to date+47.24% · −9.28%
Silmari Decoupling Gauge — year-to-date gap+56.52%p
Foreign net buying — KOSPI · KOSDAQNone · None
Retail net buying — KOSPI · KOSDAQNone · None
Investment firms’ net buying — KOSPI · KOSDAQNone · None
Pension funds’ net buying — KOSPI · KOSDAQNone · None
11 · WarningToday’s warning score of 3 = crash alert — thresholds: 3+ crash alert · 2 caution (small sample)

Warning

A window flagging in advance where today’s session calls for caution

Crash-Precursor Score 3: ADR Sub-Signal 2, Selling-Acceleration 1 — Short-Surge Counter Quiet

The crash-precursor score of 3 is held up by an ADR sub-signal of 2 (anchored to the −16.7% US-session ADR print from July 28) and a selling-acceleration sub-signal of 1 from confirmed August 7–10 flow data; these are inputs, not forecasts, and the score carries no defined action threshold in the published data.Recent short-surge events in Samsung Electronics (surge ×53.6 on July 27; ×8.8 on July 28) showed highly dispersed 5-day outcomes: −18.5% to +19.32% at three days, −5.71% to +9.09% at five days — the range is wide enough that the signal alone does not resolve direction.In the 2026 regime, rotation events (semiconductors −2%+ with defensives outperforming by 2pp+) were followed three days later by a KOSPI gain in 21 of 30 cases (up-probability 70%, average +1.92%); Tuesday’s sharp defense-sector selloff alongside chip gains is a partial inverse of that pattern and does not map cleanly to either historical bucket.

Source: Korea Exchange ·NXT (Nextrade)Korea’s alternative trading system (ATS), launched in 2025, which operates pre-market and after-hours sessions alongside the main KRX exchange and reports its own volume statistics.NXT session volume — particularly the pre-market — can reveal directional conviction from institutional and retail participants before the main KRX open.· Actual · Regular session 15:30 close · Compiled by Editorial Team.
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.