DAILY MARKET NOTE / 11 SEP 2026

Opened down 3%
Never made it back to 7,000

KOSPI -1.76% · The index recovered much of a 3% opening drop but gave up the 7,000 line it had held for two days · KOSDAQ -1.95%The main drivers of the opening plunge were WTI breaking above $100 and U.S. long-term yields rising to just below 5% · The selloff in U.S. semiconductor stocks carried into Korea’s semiconductor heavyweightsForeigners and institutions sold the two semiconductor bellwethers together, while retail investors and absorbed the selling on the other side

The overnight shock was paid for at the opening print, and prices recovered · Yet only four in ten stocks advanced

KOSPI

6,909.91

-1.76%

KOSDAQ

820.64

-1.95%

MARKET PATH / 01

The opening print was also the day’s low; two afternoon rebounds were both rejected from their highs

When did direction change, and what was working at the time?

KOSPI · 09:00~15:30Opened at 6,802.50 → 6,948.83 → closed at 6,909.91 · recovered 107.41 points from the open

OPEN6,802.50-3.29%

HIGH6,948.83-1.21%

LOW6,802.50-3.29%

CLOSE6,909.91-1.76%

THE READ

The overnight oil-and-rate shock was priced in at the opening print all at once · No new low below the open appeared for the rest of the sessionThe morning rebound stalled around 6,890, followed by a narrow range for more than three hours · Sellers also failed to push the index below the opening printThe index moved above 6,900 twice in the afternoon, but both attempts were rejected from the highs · On both occasions, more than 50 points still separated the index from 7,000The index rebound did not broaden across the market · The share of advancers was even lower on KOSDAQ than on KOSPI

OPEN · MORNING

The 6,802.50 open was the low, followed by a 90-point rebound in 30 minutes

The index opened at 6,802.50, 231.42 points below the previous close · The opening print remained the day’s lowAt 09:30, the showed a rebound toward 6,890 · It was immediately rejected, with the index back near 6,830 by 09:40From 10:00 to 12:30, the index moved in a 6,840–6,880 range · KOSDAQ’s 816.91 opening print was also its day low

MIDDAY · AFTERNOON

13:40 · around 6,910; 14:00 · back near 6,860

After another dip near 6,840 around 12:30, the index began rising from 13:30 and reached around 6,910 by 13:40It failed to hold above 6,900 and returned to the 6,860 area by 14:00 · back near the top of the morning range

Just before 15:00, 6,948.83; close 6,909.91

A 5-minute candle at 14:50 jumped nearly 40 points to around 6,930 · The next candle set the day high at 6,948.83After the high, the index fell back to around 6,910 by 15:15 and closed at 6,909.91 · 38.92 points below the high KOSPI 40.3% · KOSDAQ 35.4%

Intraday path based on KOSPI 5-minute closes · Open, high, low and close are final KRX values · The high is shown within the 5-minute candle just before 15:00 · The final 10 minutes from 15:20 are the closing auction · The horizontal dotted line marks the previous close at 7,033.92.

WHY / 02

WTI at $100 and U.S. long-term yields · the core drivers of the 3% opening plunge

Only the factors that actually explained the day’s direction

The main driver of the opening plunge was WTI breaking above $100 and U.S. long-term yields rising to just below 5%

WTI rose 6.69% on September 10 local time to close at $102.48 · concerns over a prolonged U.S.–Iran conflict were compounded by Houthi rebels taking control of Mocha on the Red Sea coastOn the same day, U.S. August rose 5.4% YoY, above the 5.3% consensus · with oil and inflation pressure converging overnight, the U.S. 10-year yield closed at 4.944%In Korea, pressure appeared in two places · weakness hit semiconductor heavyweights after the U.S. chip selloff · alongside higher U.S. yields, the 3-year KTB yield briefly broke above 4%

$102.48WTI September 10 close · up 6.69% on the day

View evidence

Brent $107.63 +6.34% · both benchmarks posted their highest closes since May 19 · WTI intraday high $103.06

Oil catalysts · President Trump said he expected fighting with Iran to end after the November midterm elections · The Wall Street Journal reported Iran had resumed ballistic-missile production · Houthi control of Mocha raised concerns over disruptions to both the Strait of Hormuz and Red Sea shipping

U.S. equities, September 10 · Dow -0.60% · S&P500 -0.58% · Nasdaq -0.65% · Philadelphia Semiconductor Index -2.66% · Micron -4.94% · Nvidia -2.26%

U.S. 10-year close 4.944% · up from 4.837% the previous day · U.S. 30-year yield was 5.360% at 15:00 local time, the highest since June 2004 according to reports · PPI rose 0.4% MoM, in line with consensus

KTB 3-year yield 4.027% at 13:44 · up 10.0bp, the highest since November 2023 · 10-year yield 4.550% according to reports

USD/KRW closed daytime trading at 1,345.9 · up 6.7 won

Caution ahead of the U.S. August CPI release was also cited in closing commentary as a factor behind the weakness

Countervailing factor · Korea Customs Service said semiconductor exports for September 1–10 reached $16.5bn, up 270.1% YoY (released the morning of September 11) · closing commentary cited this as one factor behind the narrowing losses

MONEY / 03

Foreigners and institutions sold KRW 3.5tn; retail and other corporations absorbed it

Who moved the market today

FOREIGN · KOSPI CASH

-KRW 2.304tn

No. 1 net sell: SK hynix · No. 2: Samsung Electronics · the two stocks accounted for 60.0% of KRW 3.3227tnSK hynix alone accounted for 32.4% · adding Samsung Electronics Preferred brings the Samsung Electronics group total to KRW 1.2014tnSelling extended to Hanmi Semiconductor, DB HiTek and Wonik IPS across semiconductor equipment and foundry names · the top net buy was NAVER at +KRW 36.2bn only

SK hynix-KRW 1.0771tn

Samsung Electronics-KRW 916.7bn

Samsung Electronics Preferred-KRW 284.7bn

Hanmi Semiconductor-KRW 102.2bn

INSTITUTION

-KRW 1.2235tnSamsung Electronics -KRW 570.4bn · SK hynix -KRW 495.7bn · the two stocks accounted for 48.4% of KRW 2.2027tn in net-sell amounts · same direction as foreigners · the top net buy was Samsung Electro-Mechanics at +KRW 62.3bn

INDIVIDUAL

+KRW 1.8658tnSamsung Electronics +KRW 940.3bn · SK hynix +KRW 490.0bn · Samsung Electronics Preferred +KRW 260.4bn · retail investors directly absorbed the semiconductor selling from foreigners and institutions · their top net sell was Samsung Electro-Mechanics at -KRW 42.3bn

OTHER CORP ·

+KRW 1.6492tn

KRX final close data · total market basis · closing reports also noted 18 consecutive sessions of net buying and buybacks by Samsung Electronics and SK hynix · this is similar in size to the two stocks’ total of KRW 1.6296tn, but because these are not direct stock-level other-corporation figures, they are not assigned to the two stocks individually

Futures · program trading · short selling · stock-level flows

Foreigners -KRW 680.0bn

Institutions KOSPI 200 futures+KRW 1.063tn

-KRW 1.8128tn

program trading-KRW 1.7617tn

Program trading: arbitrage -KRW 51.1bn · non-arbitrage -KRW 1.7617tn · both categories were net sellers · total selling narrowed from -KRW 2.5245tn in the previous session
KOSPI 200 futures are reported in KRW billions · retail -KRW 310.0bn
Residual outside the three investor groups +KRW 1.6617tn = other corporations +KRW 1.6492tn + other participants KRW 12.5bn
Samsung Electronics: foreigners -KRW 916.7bn · institutions -KRW 570.4bn · retail +KRW 940.3bn · back-solved outside the three investor groups +KRW 546.8bn / SK hynix: foreigners -KRW 1.0771tn · institutions -KRW 495.7bn · retail +KRW 490.0bn · back-solved outside the three investor groups +KRW 1.0828tn
Foreigners’ next-largest net sells: Doosan -KRW 45.9bn · DB HiTek -KRW 41.5bn · Samsung C&T -KRW 39.2bn · Wonik IPS -KRW 27.3bn / Net buys: Woori Financial Group +KRW 34.6bn · Celltrion +KRW 28.0bn · S-Oil +KRW 24.2bn
Institutions’ next-largest net sells: SK Square -KRW 89.6bn · NAVER -KRW 52.9bn · Celltrion -KRW 50.6bn / Net buys: HD Hyundai Heavy Industries +KRW 48.0bn · Samsung C&T +KRW 39.4bn · Doosan +KRW 37.2bn
Retail net buys next included Hanmi Semiconductor +KRW 144.4bn · SK Square +KRW 81.0bn / Net sells: Samwha Capacitor -KRW 40.2bn · Woori Financial Group -KRW 31.7bn · HD Hyundai Heavy Industries -KRW 31.3bn
Concentration ratios use the sum of that investor group’s net-buy (or net-sell) amounts by stock as the denominator, not the market-wide net figure · summed from raw KRX data · total stock-market basis combining KOSPI and KOSDAQ · Samsung Electronics accounted for 31.1% of retail net buys totaling KRW 3.0215tn
KOSPI KRW 2.34tn · share 9.5%, up from 5.32% the previous day · by stock: SK hynix KRW 609.7bn (10.1% share) · Samsung Electronics KRW 430.2bn (9.3%) · Hanmi Semiconductor KRW 148.2bn (40.9%) · KOSDAQ KRW 0.42tn, 5.7% · figures combine KRX and NXT, so the denominator differs from KOSPI turnover
KOSDAQ foreigners -KRW 313.6bn · institutions -KRW 215.9bn · retail +KRW 511.7bn

SECTOR / 04

Where the market was strong · where it was weak

Today’s distribution of strength and weakness, not a ranking table

STRONG

KOSPI Construction+1.90%

KOSPI Insurance+1.56%

KOSPI Real Estate+1.43%

KOSPI Electricity & Gas+1.06%

WEAK

KOSDAQ Machinery & Equipment-3.16%

KOSDAQ Electrical & Electronics-2.84%

KOSPI Electrical & Electronics-2.66%

KOSPI Chemicals-1.65%

The weakest end was concentrated in Electrical & Electronics in both markets and KOSDAQ Machinery & Equipment, where semiconductor and equipment names sit · , all 15 constituents of KRX Semiconductor Top 15 fellThe strongest end was Construction, Insurance and Real Estate · 11 of 13 insurance stocks and 26 of 37 construction stocks rose, showing broad industry strengthThe financial axis that showed relative strength on a rising-rate day was Insurance and the high-dividend financial themeKOSPI Electricity & Gas +1.06% had only 4 of 10 stocks advance · not read as broad industry strength

Industry evidence

Of 46 KRX industry indices, 17 rose and 29 fell · KOSPI: 11 of 24 up · KOSDAQ: 6 of 22 up
Weakness details · KOSPI Electrical & Electronics: 52 of 84 stocks down · KOSDAQ Electrical & Electronics: 201 of 316 down · KOSDAQ Machinery & Equipment: 115 of 183 down · KOSDAQ Non-Metals -3.98% was excluded from the list because the industry has only 15 stocks
Of 39 themes, 10 rose and 29 fell · leaders: KRX Shipbuilding TOP10 +2.55% (8 of 10 stocks up) · KOSPI 200 Financial High Dividend TOP 10 +2.47% · KRX Prime Office REITs +1.31%
Weak themes · KRX Semiconductor Top 15 -3.95% · KOSDAQ TOP 10 -3.92% · KRX K-AI Secondary Battery -3.40% · KRX AI Semiconductor -3.32% · KRX Secondary Battery TOP 10 -2.44% (all 10 stocks down)
Company-specific event · HD Hyundai Heavy Industries +5.62% · after announcing KRW 1.0722tn of facility investment on September 10 (KRW 833.6bn for mid-sized power-generation engines · KRW 238.6bn for SMR main equipment), brokerages raised target prices · on the announcement day the stock -2.16%
effective date · all four stocks whose weights were set to rise on September 10 fell · Hanmi Semiconductor -8.70% · Jusung Engineering -5.43% · Leeno Industrial -4.18% · EO Technics -2.09%
Among the top 10 stocks by market capitalization: 1 up · 1 flat · 8 down · KB Financial +2.60% · Samsung Electro-Mechanics 0.00% / Samsung Electronics Preferred -4.78% · SK Square -4.05% · Samsung Electronics -3.53% · SK hynix -2.21% · Hyundai Motor -1.67% · LG Energy Solution -1.37% · Samsung Life Insurance -0.65% · Samsung Biologics -0.56%
Industry and theme indices are not mixed into the same ranking table · industry returns are indices, not sector-level net inflow amounts

CHANGE / 05

Yesterday’s questions, answered

Checking today against the prior session’s conditions

YESTERDAY → TODAY

Foreign net selling in KOSPI the day after expiry was KRW 2.304tn, well above KRW 1tn · a second straight day above KRW 2tn · was also net selling, tilting the interpretation away from aloneThe U.S. 10-year closed at 4.944%, above the 4.85% threshold · the domestic confirmation was mixed · Chemicals -1.65% remained on the weak side, while Electricity & Gas +1.06% moved to the strong sideKOSPI failed both conditions: a third straight close above 7,000 and a recovery in the share of advancers to 50% · the ratio fell further from 46.0% to 40.3%

Foreign KOSPI cash equities

-KRW 2.482tn

→

-KRW 2.304tn

U.S. 10-year close

4.837%

→

4.944%

KOSPI share of advancers

46.0%

→

40.3%

Market-breadth formula

KOSPI: 1 limit-up · 369 up · 73 flat · 475 down · 0 limit-down · 370 advancers · 370/918 = 40.3%
KOSDAQ: 11 limit-up · 607 up · 124 flat · 1,004 down · 0 limit-down · 618 advancers · 618/1,746 = 35.4% · previous day 47.6%
Numerator = advancers + limit-up stocks; denominator = all stocks including unchanged · both market ratios match the dashboard printout
Foreigners’ two-day total -KRW 4.786tn · KOSPI turnover KRW 19.67tn · 84% of the five-day average

NEXT / 06

What to watch next session

Conditions that can be scored from actual outcomes, not probabilities

Does the U.S. 10-year close above 5% after the CPI release?

This tests whether the oil-and-rate pressure that drove today’s plunge carries through the weekend · a close above 5% would mean the September 14 open also starts under rate pressure · confirm by whether insurance strength and semiconductor weakness persist together

Does foreign net selling in SK hynix and Samsung Electronics combined fall below KRW 1tn?

The two-stock total was KRW 1.9938tn today · below KRW 1tn would signal that the intensity of the two-day selling is easing · above KRW 1tn again would mean the two semiconductor bellwethers continue to cap the index

Does KOSPI close above today’s opening—and day-low—level of 6,802.50?

There was no new intraday low after the opening shock · also watch whether other corporations extend their net-buying streak to a 19th session · a close below 6,802.50 would mark the limit of the buying support

POST-CLOSE → NEXT SESSION · 9/14

9/11
21:30

U.S. August CPI · released

Headline: +0.4% MoM (consensus +0.4% · previous +0.1%) · +3.4% YoY (consensus +3.4% · previous +3.4%)
+0.3% MoM (consensus +0.2% · previous +0.2%) · +2.4% YoY (consensus +2.4% · previous +2.5%)
Gasoline rose 3.9% MoM, accounting for more than one-third of the monthly increase

9/14
09:00

Korean market open

The first session to reflect core CPI running 0.1%p above consensus, along with weekend moves in oil and U.S. yields

Next week · Sep. 15–18

9/17
03:00

Federal Reserve rate decision

September 16, 14:00 local time · economic projections released together

9/18
Midday

Bank of Japan rate decision

September 17–18 meeting · result due around midday Korea time on the 18th

The index climbed back above its opening print, but more than 100 more stocks fell than rose on Friday.

Sources · Data basis

Reference date: 2026.09.11 · Korean market close confirmed at 15:30
Index · market breadth · turnover · program trading · KOSPI 200 futures · short selling · top market-cap stocks · market-indicator JSON (Naver Finance index daily data · final KRX values)
Investor totals · based on Korea Exchange closing reports published around 16:00 on September 11 · KOSPI foreigners, institutions, retail and other corporations; KOSDAQ three investor groups · aligned to the same around-16:00 basis as stock-level flows
Intraday path · KOSPI 5-minute closes · open, high, low and close use the four final KRX values
Stock-level flows · raw KRX investor-trading data at the close · total stock-market basis · concentration denominators use sums from the raw data
Industries · themes · Korea Exchange KRX Index industry and theme indices at the close
Program trading · futures · short selling · final KRX values · KOSPI 200 futures reported in KRW billions (foreign -KRW 680.0bn matches closing reports) · short selling combines the regular KRX and NXT markets
Overseas · U.S. equities, Philadelphia Semiconductor Index and individual U.S. semiconductor stocks use September 10 closes · U.S. 10-year close 4.944% · WTI and Brent use September 10 closes · U.S. 30-year 5.360% is the Tradeweb FTSE 15:00 ET reading
U.S. producer prices · August data released September 10 at 08:30 local time · +5.4% YoY · +0.4% MoM
Reports · President Trump’s remarks on the expected end date of fighting with Iran; The Wall Street Journal report on Iran resuming ballistic-missile production; Houthi control of Mocha
Korean rates · KTB 3-year and 10-year yields use intraday values reported at 13:44
USD/KRW · daytime trading close 1,345.9
Exports · Korea Customs Service September 1–10 trade data (released September 11)
Other corporations · final KRX figures as cited in closing reports · consecutive net-buying days and buyback context follow closing-market reports · stock-level values outside the three investor groups are back-solved from raw data
Company · HD Hyundai Heavy Industries facility-investment size and purpose (announced September 10) and brokerage target prices are based on reports
Individual stock returns · top 10 market-cap stocks use final KRX regular-session closes · Hanmi Semiconductor and HD Hyundai Heavy Industries use final closes from KRX short-selling data · Jusung Engineering, Leeno Industrial, EO Technics and U.S. semiconductor names follow closing-market reports
Released after the Korean close · U.S. August CPI (September 11, 08:30 local time): actual, consensus and previous readings
Schedule · Federal Reserve rate decision September 16 at 14:00 local time · Bank of Japan meeting September 17–18

Previous issue · www.snowshagal.com

HalfwayBack

Opened down 3%Never made it back to 7,000