The Silmari

A daily data newsletter on the Korean stock market — silmari, ‘a clue: the loose end that unravels the knot’

⑤ After-Hours 18:002026.08.11 Tue · No. 9Neutral — sentiment gauge score 0.8 (stage: neutral); vol20 component at 95th percentile (expanding, 2026 regime); other components including margin and short-surge are uncollected today.

⑤ After-Hours · published 18:00 KST · after the regular session · Note: flow figures are preliminary as published just after the close; the exchange’s confirmed figures appear in that day’s Final Edition (20:00 KST).

① Pre-Open07:30 ② Early Session10:00 ③ Midday12:00 ④ Closing16:00 ⑤ After-Hours18:00 ⑥ Final20:00

01 · VerdictRegular session confirmed 15:30 KST

verdict at evening

KOSPI Closes +0.73% at 6,345 as Samsung Surges; Morning Call Missed

The KOSPI ended Tuesday, August 11 (2026) up +0.73% at 6,345.53, reversing a morning dip to a session low of 6,213.78 before peaking at 6,405.81 — a high-low range of 192.03 points (3.09%).The KOSDAQ added +0.39% to close at 857.84; the morning’s call for a decline in both indices missed — the day’s call is recorded as a miss.

Key points

01KOSPI closed +0.73% at 6,345.53; session low of 6,213.78 hit at 09:07, high of 6,405.81 reached at 13:32 — a 3.09% intraday range. Morning directional call of –1.5% to –2.5% missed.

02Samsung Electronics led KOSPI turnover at ₩5,510.9bn, closing up +4.13%; SK hynix added +0.35% with ₩5,214.7bn traded. Defense names shed ground: Korea Aerospace Industries –12.07%, Hanwha Ocean –5.72%, Hyundai Rotem –5.86%.

03Foreigners were net sellers of ₩1,490.9bn on KOSPI today (provisional); over the past quarter their net selling totals ₩101,329.5bn. Retail investors were net buyers of ₩900.3bn today; investment trusts net bought ₩632.1bn.

04Jusung Engineering surged +12.15% to lead KOSDAQ turnover at ₩519.0bn; Alteogen fell –5.89%. KOSPI breadth: 573 advances vs 288 declines (ADRAdvance-Decline RatioThe number of advancing issues divided by the number of declining issues on a given exchange for a given session.An ADR above 1.0 signals that advancers outnumbered decliners; today’s KOSPI ADR of 1.99 means roughly two stocks rose for every one that fell, even as the headline index gained only 0.73%. 1.99). Japan’s market was closed today for Mountain Day.

02 · NXTNextrade (NXT) — Korea’s Alternative Trading SystemAn alternative exchange launched alongside KRX that offers extended trading hours including pre-market and after-market sessions; its figures are separate from KRX main-board totals.NXT after-market activity gives the earliest indication of how market participants are repositioning once the KRX regular session closes at 15:30 KST.NXT after-hours reference time — not yet set

Evening disclosures —Short sellingShort sellingSelling borrowed shares first, betting the price will fall.A rising balance means more money is betting on a decline.balance

A window on whether the regular session’s move carried into the evening alternative venue

NXT After-Market Snapshot: 319 Advancers, ₩13,632.7bn Traded Across 608 Issues as of 17:25

As of the 20-minute-delayed snapshot timestamped 17:25 KST — NXT (the alternative exchange, Nextrade) figures only, not KRX main-board data, and not yet confirmed for the day — 608 issues were tracked with 319 advancers, 267 decliners, and aggregate turnover of ₩13,632.7bn.Samsung Electronics led NXT turnover at ₩3,520.7bn (up +3.7% on NXT), followed by SK hynix at ₩3,077.4bn (+0.14%); confirmed daily NXT session totals will be available in the final (20:00) edition.

03 · Gap risksRisk → same condition in the past → outcome distribution

Tomorrow morninggap risks 4names

A window naming in advance what could shake tomorrow’s opening price

Defense Stocks Retreat Up to 12% While Samsung Electronics Rebounds 4.13% — Sector Divergence Dominates Tuesday’s Tape

ADR

Warning score total: 3

signal 2 points

Short-interest surge

Warning score total: 3

signal 0 points

Selling acceleration

Warning score total: 3

signal 1 point

Sentiment 90+

Warning score total: 3

signal 0 points

05 · PrincipleEvening Trading Principles reference time — not yet set

Evening Trading Principles

A window recording the trading principles to hold to on the evening of a crash day

Crash-Precursor Score Sits at 3 with Volatility Component at 95th Percentile — Elevated Intraday Range Warrants Position-Size Discipline

The crash-precursor score for Tuesday, August 11 (2026) stands at 3 out of a possible higher reading, driven by ADR (2 points) and a sell-acceleration signal (1 point); the short-surge sub-score is zero and the sentiment-90+ sub-score is zero.The vol20 component of the sentiment gauge is at the 95th percentile of its expanding 2026-regime distribution, indicating that realized volatility remains elevated relative to this year’s baseline — a condition in which intraday ranges like today’s 3.09% KOSPI swing are consistent with the regime average of 4.13% for Tuesdays (2026, n=30).In elevated-volatility regimes, standard risk-management practice calls for sizing positions relative to the observed daily range rather than to average quieter-period moves; today’s data do not, on their own, resolve the direction of that range for Wednesday.