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KOSPI gaps up at open, chips lead; KOSDAQ lags behind — Korea Market Morning Session, Aug 12, 2026

The KOSPI opened at 6,435.6 on Wednesday, August 12 (2026), surged to an intraday high of 6,509.04 by 9:28 before pulling back to the 6,460–6,480 range near 10:00, with foreigners provisionally net buyers of ₩394.6bn on the main board.The KOSDAQ opened at 853.01 but drifted lower through the half-ho

The Silmari
A daily data newsletter on the Korean stock market — silmari, ‘a clue: the loose end that unravels the knot’
② Early Session 10:002026.08.12 Wed · No. 10Crash-precursor score: 3 of a possible maximum (ADR signal active, selling-acceleration signal active; short-surge and sentiment-90+ signals not triggered) — no single-day reading is definitive, and today’s score reflects data through the prior session.
② Morning Session · published 10:00 KST · session in progress
01 · VerdictRegular session confirmed 15:30 KST

10:00verdict at this hour

KOSPI gaps up at open, chips lead; KOSDAQ lags behind

The KOSPI opened at 6,435.6 on Wednesday, August 12 (2026), surged to an intraday high of 6,509.04 by 9:28 before pulling back to the 6,4606,480 range near 10:00, with foreigners provisionally net buyers of ₩394.6bn on the main board.The KOSDAQ opened at 853.01 but drifted lower through the half-hour mark before partially recovering, with retail investors carrying the session and foreigners provisionally net sellers of ₩101.4bn.

Key points
01Chip complex leads KOSPI higher: Samsung Electronics opened at ₩241,000 and reached ₩250,500 by 9:16; SK hynix touched ₩1,478,000 at 9:25. The semiconductor sector posted a provisional +2.11% sector reading, with Samsung Electro-Mechanics (+3.57%) and SK Square (+6.67%) also advancing.
02KOSDAQ diverges from KOSPI: While the KOSPI was well above its open near 10:00, the KOSDAQ slipped below its open of 853.01 to a session low of 839.86 at 9:30 before recovering to the 848849 range — a two-market split with retail investors the sole net buyers on KOSDAQ at ₩190.0bn provisionally.
03Morning call — first provisional scorecard (intraday provisional, final at close): P1 KOSPI ↑ (+0.5+1.5%) → actual near +2.27% △ direction correct, magnitude low; P2 KOSDAQ flat (-0.3+0.5%) → actual near 1.6% ✗ miss; P3 Samsung Electronics +1+2% → actual near +3.34% △; P4 SK hynix +1.5+2.5% → actual near +1.61% ✓; P5 Jusung Engineering flat–down → actual near 1.52% △.
04Wednesday seasonal context: In the 2026 regime (n=29), Wednesdays have shown an average KOSPI move of +1.05% with an 79% advance rate; foreigners net buy on 45% of 2026 Wednesdays — today’s early foreign Net Purchase / Net BuyingThe difference between an investor group’s total purchases and total sales in a given period; a positive figure means the group bought more than it sold.Tracking which investor group — foreigners, institutions, or retail — is the net buyer or net seller on a given day is the primary lens for reading short-term supply and demand dynamics on the KRX. is consistent with but does not guarantee that pattern.
02 · SnapshotThrough 10:00 · Yahoo 5-min candle approximation (may have minor variance vs. exchange official)

10:00Snapshot

A window that records the market at that hour, like a photograph

Nikkei up 0.14% early; won firms to 1,411.78 per dollar; Philadelphia Semiconductor Index (SOX)A U.S. equity index tracking roughly 30 companies involved in the design, distribution, manufacture, and sale of semiconductors.Because Korean chipmakers such as Samsung Electronics and SK hynix derive a significant share of revenue from global semiconductor demand cycles, same-day SOX moves are widely watched as a leading directional signal for KOSPI chip stocks. closed +0.87% overnight

KOSPI at 10:00Open6,438.50· High6,509.04(09:25) · Low6,413.50(09:05) · as of 09:356,488.07
KOSDAQ at 10:00Open854.85· High854.85(09:00) · Low839.86(09:30) · as of 09:35844.73
03 · Top 10 checkpointsYahoo 5-minute bars · through 10:00

Top by trading value10— snapshot

A window on how the top trading-value names have moved up to this hour

Samsung Electronics and LG Electronics pace KOSPI top-ten by turnover in early trade

Through approximately 9:52, the KOSPI’s two heaviest-traded names were Samsung Electronics at ₩1,249.7bn and SK hynix at ₩899.3bn in provisional turnover — together they account for the bulk of index-level movement in the opening hour.LG Electronics (₩132.8bn) and SK Square (₩164.4bn) also attracted outsized early interest relative to their usual footprint, consistent with the electronics and semiconductor sector reading of +3.62% and +2.11% respectively at this hour.

Top 10 by trading value — prior close · open · Opening GapThe difference between a security’s or index’s previous closing price and its opening price the next session, leaving a visible gap on a price chart.A large opening gap — especially after overnight news — often triggers elevated early volatility as the market price-discovers the new level; gap-chasing trades carry higher reversal risk. · 10:00 snapshot (may have minor variance vs. exchange official)
StockPrior closeOpenGapLast at 10:00High (time)Low (time)
Samsung Electronics239,495243,500+1.67%249,500 (10:00)250,500 (09:15)241,000 (09:00)
SK hynix1,424,9511,456,000+2.18%1,464,000 (10:00)1,478,000 (09:25)1,440,000 (09:10)
Samsung Electro-Mechanics1,261,9671,288,000+2.06%1,314,000 (10:00)1,322,000 (09:25)1,275,000 (09:00)
SK Square944,970982,000+3.92%1,014,000 (10:00)1,018,000 (09:25)970,000 (09:00)
Kumho E&C11,49011,620+1.13%14,310 (10:00)14,490 (09:30)11,340 (09:00)
LG Electronics181,708184,200+1.37%195,200 (10:00)197,800 (09:10)184,200 (09:00)
Daewon Cable14,52015,100+3.99%15,480 (10:00)15,740 (09:25)15,020 (09:00)
Samsung Electronics (Pref.)180,193182,500+1.28%185,000 (10:00)186,400 (09:15)180,500 (09:00)
NAVER213,993215,000+0.47%218,000 (10:00)220,500 (09:10)214,500 (09:00)
Korea Kolmar107,896114,100+5.75%128,800 (10:00)129,200 (09:35)109,000 (09:10)

LG Electronics set its session low at the open (₩184,200 at 9:00) and its intraday high at 9:47 (₩202,000), a range of ₩17,800 within the first 47 minutes — the widest absolute intraday swing among the KOSPI top-ten by turnover.Kolmar Korea was still climbing at the data cut-off, hitting its session high of ₩132,600 at 9:52, while NAVER’s intraday high of ₩220,500 was set as early as 9:10 and the price had since retreated to the open level of ₩216,500.

04 · Up · DownReason labels: [News] confirmed · [Pattern] inferred

Gainers5· Decliners5— snapshot

A window on the biggest gainers and decliners, and the reasons behind them

KOSPI breadth tilts positive as chips and beauty names surge; shipbuilders retreat

On the KOSPI, gainers included Kumho Electric (+29.9%), Kumho Engineering & Construction (+23.5%), Kolmar Korea (+17.7%), Cosmax (+17.62%), and Iljin Electric (+16.99%) — a mix of cosmetics OEM names and a construction stock alongside the semiconductor complex, suggesting the advance is not concentrated in a single theme.On the retreat side, HD Korea Shipbuilding & Offshore Engineering fell 4.15% and HD Hyundai Heavy Industries 3.98%, while OCI Holdings dropped 5.48% and Hanwha Solutions slipped 1.51% — shipbuilding and solar names account for the bulk of the KOSPI’s decline column.On the KOSDAQ, Delicious (15.86%), Pearl Abyss (14.09%), Simtech (8.34%), and Alteogen (4.27%) led the decline, while Silicon2 (+10.11%) and KBI Metal (+9.3%) moved sharply higher — the KOSDAQ’s intraday picture is markedly more mixed than the KOSPI’s.

Gainers —5:00as measured at this hour
Kumho Electric+29.90%· trading value 16.8B won
Kumho E&C+23.50%· trading value 159.0B won
Korea Kolmar+17.70%· trading value 56.7B won
Cosmax+17.62%· trading value 34.0B won
Namhwa Construction (KOSDAQ)+17.08%· trading value 18.0B won
Losers —5:00as measured at this hour
Delicious (KOSDAQ)−15.86%· trading value 95.2B won
Pearl Abyss (KOSDAQ)−14.09%· trading value 30.7B won
Simtec (KOSDAQ)−8.34%· trading value 34.6B won
Ollix (KOSDAQ)−7.66%· trading value 12.0B won
Fidelix (KOSDAQ)−5.76%· trading value 12.2B won
Historical contextSelection: turnover of ₩10bn or more · machine ranking by percentage change.
Source: Korea Exchange ·Nextrade (NXT)Korea’s alternative trading system, which launched in 2026 and operates pre-market and after-market sessions alongside the main KRX session.NXT pre-market turnover and price moves provide the earliest observable signal of domestic investor sentiment before the 9:00 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.