DAILY MARKET NOTE / 15 SEP 2026

Semiconductors Took the First Hit,
The Rest Fell Today

KOSPI -0.85% · 6,627.26 · down for a fourth straight sessionSemiconductors had already taken the brunt of the AI-slowdown narrative in the previous session · additional damage was limited todayWhat weighed on the index today was the renewed afternoon rise in U.S. long-term yields and oil · shipbuilding, defense, financials and insurance fell underneathKOSDAQ +0.70%, moving the other way

Bad news priced first is not priced twice.

MARKET PATH / 01

Morning rebound given back as yields and oil rose again in the afternoon

When did direction change, and what was working then?

KOSPI · 09:00—15:30Open 6,659.25 → around 11:50 6,715.46 → around 14:10 6,582.20 → close 6,627.26

OPEN6,659.25-0.38%

HIGH6,715.46+0.47%

LOW6,582.20-1.53%

CLOSE6,627.26-0.85%

THE READ

The morning rebound looked like a retracement after the previous session's 3%+ decline · hard to call it a rally driven by new informationThe new information behind the afternoon selloff was yields and oil rising again in Asian trading · not the 5% break itself, which was known before the openInternal market breadth was worse than the index decline · on KOSPI, decliners outnumbered advancers by more than two to oneThe two largest stocks by market cap barely fell, limiting the index decline relative to market breadth

OPEN · MORNING

The Morning Started With the Bad News Known—and Moved Higher

Opened 25.12 points below the previous closeThe U.S. 10-year Treasury's break above 5% and the AI-slowdown concerns were already known at the openThe rebound reached the day's high around 11:50 · recovered as far as 31.09 points above the previous close

AFTERNOON

Direction Reversed After 13:00

In Asian trading, the U.S. 10-year again moved above 5% and rebounded into the $107sWeakened again after 13:00, reaching the day's low around 14:10133.26 points from the high to the low

Close Recovered 45 Points From the Low, as the Two Markets Diverged

Closed 45.06 points above the lowKOSDAQ moved the other way over the same period, rising +0.70%KOSPI turnover fell to KRW 16.2tn from the KRW 21tn range in the previous session

Intraday direction line connecting four confirmed points—open, high, low and close—not a minute-by-minute chart.

WHY / 02

Yields and Oil Rose Again in the Afternoon; Semiconductor Bad News Had Already Been Priced

Only the factors that actually explained the day's direction

The new information behind the afternoon selloff was yields and oil rising again in Asian trading

Its intraday move to 5.012% on Sep. 14 local time—the first touch of 5% since Oct. 2023—was already known before Korea opened · it was not itself new afternoon bad newsWhat was new in the afternoon was the 10-year moving back above 5.02% in Asian trading and Brent rebounding into the $107sAt that point, the case supporting the rebound—“the bad news is already priced in”—fell awayUSD/KRW moved the same way to 1,359.2 · up 12.1 won from the previous session

5.02%Asian trading · U.S. 10-Year Treasury

Show evidence

U.S. 10-year Sep. 14 local close 4.961% · previous session 4.975% · intraday high 5.012%

Brent Sep. 14 local close $105.68 · $107s in Asian trading · WTI $103.06

Dow -0.29% · S&P 500 -0.48% · Nasdaq -0.56% · VIX 17.10, +7.95%

Fed funds 25bp hike probability in the 90% range · just before the Sep. 15–16 local-time Fed meeting

USD/KRW at highest since Sep. 2 · intraday 1,361.1

“Further increases in yields and oil diluted the sense that risks were already priced in and weakened dip-buying” · Daishin Securities comment cited

AI Slowdown Narrative Met Higher Yields and Oil, Sending the -5.86%; Korea Had Already Priced Much of It the Previous Session

Reports that Anthropic's Dario Amodei called for slowing the pace of development, with Sam Altman and Elon Musk said to agree, were tied to concerns over reduced capex · higher yields and oil were also at work in the same U.S. sessionKorea had already priced much of it in the previous session · Sep. 14 Samsung Electronics -4.05% · SK hynix -6.35%Today: Samsung Electronics -0.20% · SK hynix -0.41% · KOSPI Electrical & Electronics -0.24%, limiting the additional hit

-5.86%Philadelphia Semiconductor Index · Sep. 14 local

Show evidence

Nvidia -3.36% · Intel -5.59% · AMD -4.40% · Micron -5.25% · Broadcom -4.77%

Marvell Technology -7.32% · Lam Research -8.29% · ASML -7.25% · equipment and higher-multiple stocks fell more

SK hynix ADR -7.60% · diverged from Korea’s regular-session close

Meta +2.71% · Alphabet +3.22% · stocks split toward expectations of lighter investment burdens

The slowdown remains at the level of comments and reporting; no policy has been finalized

MONEY / 03

Foreigners Kept Selling Mega-Cap Semiconductors; Other Corporations Were on the Other Side

Who moved the index today

FOREIGN TOTAL · KOSPI CASH

-KRW 1.5711tn

Foreign net selling was again concentrated in the two mega-cap semiconductor names · SK hynix -KRW 1.0024tn · Samsung Electronics -KRW 291.1bn · combined -KRW 1.2934tnEven so, both stocks closed down less than 1% · their already-sharp decline in the previous session and buying on the other side both matteredOther corporations were on the other side at +KRW 1.6430tn · a day when selling size alone could not explain the price action

SK hynix-KRW 1.0024tn

Samsung Electronics-KRW 291.1bn

Program trading · detailed flows · series basis

KOSPI -KRW 904.5bn

Program trading-KRW 817.5bn

Arbitrage program-KRW 87.0bn

KOSPI turnoverKRW 16.2tn

Arbitrage and non-arbitrage moved in the same direction · cash 1,042.46 · futures 1,039.80; closing times differ, so not used as directional evidence
Foreign net buying was scattered · SK Square · Samsung SDI · LG Electronics · Samsung Electro-Mechanics, in that order; the No. 1 amount was roughly one-thirtieth of the top net-sell amount
Institutional net buying · Samsung Electronics preferred · KB Financial Group · LG Energy Solution · Hanmi Pharmaceutical, in that order
Turnover · KOSPI fell from the KRW 21tn range in the previous session · KOSDAQ stayed in the KRW 6tn range, similar to the previous session
· 6.69% of KOSPI regular-market turnover · denominator differs from KOSPI turnover because the figure combines Korea Exchange and Nextrade · Hanmi Semiconductor, Hanwha Aerospace and Jusung Engineering ranked high individually
Series basis · investor totals are confirmed regular-session close figures · stock-level flows come from a separate KRX investor-trading query · the two series are not added together or converted into shares within the same card

SECTOR / 04

Where It Was Strong · Where It Was Weak

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

Strength was narrowly concentrated in the non-China battery supply chain, while weakness clustered in shipbuilding, defense, financials and insurance.The common same-day catalyst for secondary batteries was the U.S. Department of Transportation's criticism of Ford's cooperation with China's CATL · expectations of gains for non-China supply chains attached to the moveSamsung SDI's target price was raised from KRW 600,000 to KRW 730,000 the same day, but SK Innovation's KRW 200,000 target was driven mainly by refining and lubricant earnings forecasts, while POSCO Future M's KRW 290,000 target was maintained rather than raised · the three are not treated as one battery catalystNo common same-day catalyst was identified that explains shipbuilding, defense, financials and insurance together · we do not infer a bank/insurance causal story simply from yields touching 5%Of KOSPI's 24 , only four rose · 14 of 22 KOSDAQ industries rose, leaving the two markets moving in different directions

STRONG

KRX K-AI Secondary BatteryTheme+3.38%

KRX Secondary Battery TOP 10Theme+2.88%

Medical & Precision EquipmentKOSPI Industry+1.23%

ConstructionKOSPI Industry+0.84%

WEAK

KRX Shipbuilding TOP10Theme-5.48%

KRX K-AI Defense TOP5+Theme-4.17%

Transportation Equipment & PartsKOSPI Industry-3.35%

InsuranceKOSPI Industry-3.08%

Industry evidence

Of the KRX’s 46 industry indices, 18 rose and 28 fell · KOSPI: 4 of 24 up · KOSDAQ: 14 of 22 up
KOSPI weakness continued · Distribution -2.75% · Financials -2.18% · Transportation & Warehousing -2.15% · Securities -2.14% · Electricity & Gas -1.63% · Food, Beverage & Tobacco -1.56% · Machinery & Equipment -1.53%
KOSPI Electrical & Electronics -0.24%, falling less than KOSPI Manufacturing -0.57% · KOSDAQ Electrical & Electronics +0.95%
Of 39 theme indices, 10 rose and 29 fell · Electric Vehicle Top 15 +1.12% · K-AI Biotech KOSDAQ +1.81%
High-dividend indices weakened together · KOSPI 200 Financial High Dividend TOP 10 -2.24% · Financials & Holdings High Dividend -1.60% · KRX-Akros High Dividend 20 -1.59% · Dividend Growth 50 -1.54% · KOSPI High Dividend 50 -1.37%
Among the 10 largest stocks by market cap, only LG Energy Solution +3.98% and Samsung Electronics preferred +2.02% rose · Samsung Life -4.19% · KB Financial Group -3.19% · Samsung Electro-Mechanics -1.50% · Hyundai Motor -1.21%
Advancers and decliners · KOSPI: 1 limit-up, 254 up, 40 unchanged, 623 down, 0 limit-down · KOSDAQ: 8 limit-up, 788 up, 101 unchanged, 842 down, 0 limit-down · counts are shown because ratios can vary by query time
A rising industry index did not mean most constituent stocks rose · KOSDAQ Transportation Equipment & Parts, the day’s top industry at +4.04%, had 31 advancers and 39 decliners among 77 names · KOSPI Construction +0.84% had 12 up and 22 down among 37 · KOSDAQ Electrical & Electronics +0.95% also had 144 up and 145 down
Industry returns are market-cap-weighted indices, not sector-level net inflow amounts

CHANGE / 05

Yesterday's Question, Answered

Checking the condition set in the previous report

YESTERDAY → TODAY

Yesterday’s question was: “Will combined foreign net selling of SK hynix and Samsung Electronics fall below KRW 1tn?” · today’s answer: KRW 1.2934tnIt did not fall below KRW 1tn, but shrank to less than half of roughly KRW 3tn in the previous sessionMore notable than the lower total was the price action · both stocks fell far less than in the previous session

Foreigners · SK hynix + Samsung Electronics net selling

About KRW 3tn

→

KRW 1.2934tn

Direction of memory and semiconductor index

Diverged

→

Micron -5.25% · index -5.86%

Whether Brent held above $108

$108.19

→

$105.68

CATALYST / 06

HD Hyundai Heavy Industries Union Expands Strike, an Individual Negative Confirmed Amid Shipbuilding Weakness

The one event that was actually priced today

KRX Shipbuilding TOP10 · theme index · all 10 constituents fell

-5.48%

The Korean Metal Workers' Union plans to extend strike time to seven hours a day from Sep. 16–18

WHAT · Strike details

Four-hour strikes on Sep. 14 and 15 · planned expansion to seven hours per day from Sep. 16–18No major disruption to shipyard operations has been confirmed so far

TERMS · Bargaining terms

Union demands a KRW 149,600 increase in base pay · company offers a flat KRW 110,000 increase21 rounds of bargaining since Jun. 2 · settlement before Chuseok remains the stated goal

IMPACT · Company & shareholder impact (interpretation)

With a thick order backlog, a strike weighs more on delivery schedules and revenue-recognition timing than on the amount of work itselfBut no operational disruption has yet been confirmed, so the impact has not yet translated into earnings numbers

MARKET · Market reaction

HD Hyundai -8.7% · HD Korea Shipbuilding & Offshore Engineering -6.7% · Samsung Heavy Industries -6.3% · HD Hyundai Heavy Industries down in the 5% rangeEven stocks not directly party to the strike fell by similar amounts · this is an individual negative confirmed within the shipbuilding selloff, not presented as the cause of the entire sector’s declineHanwha Aerospace also fell -6.5% the same day, with defense stocks weak as well, leaving KOSPI Transportation Equipment & Parts -3.35%

NEXT / 07

What to Watch Next

Conditions that can actually be scored, not probabilities

Does net buying by other corporations in KOSPI stay above KRW 1tn?

Today +KRW 1.6430tn · if this falls below KRW 500bn, the bid countering foreign selling thins out · Samsung Electronics and SK hynix are scheduled to end on Nov. 21 and Nov. 19, respectively

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

Sep. 14 local close 4.961% · intraday 5.012% · back above 5.02% in Asian trading · a close above 5% would leave intact the rationale behind this afternoon’s decline · score it on the next two closes before the Fed decision at 03:00 KST on Sep. 17

Do KOSPI decliners fall below twice the number of advancers?

Today: 254 up vs. 623 down · if this gap does not narrow even on an index rebound, the structure in which the two largest stocks carry the index will persist · KOSDAQ was nearly even at 788 up vs. 842 down

TONIGHT

9/15
22:30

U.S. Market Open

First day of the Fed meeting · watch whether semiconductor losses continue for a second session after reports about slowing AI development

NEXT SESSION · 9/16

9/16
09:00

Korea Market Open

First session to watch together whether yields and oil step higher again and whether other-corporation buying continues at the same scale

9/16
21:30

U.S. August Retail Sales

Consumer data released on the final day of the Fed meeting

Sep. 17–18 Macro Calendar

9/17
03:00

U.S. Federal Reserve Rate Decision

Sep. 15–16 local-time meeting · 25bp hike probability currently in the 90% range

9/17
20:00

Bank of England Rate Decision

Another central-bank decision in the same week, the day after the Fed

9/18
Midday

Bank of Japan Rate Decision

Sep. 17–18 meeting · decision due around midday KST on the 18th

Decliners outnumbered advancers by more than two to one, but the two largest stocks by market cap held their losses inside 1%.

Sources · Data Basis

As of 2026.09.15 · indices, industries, themes and individual stock closes use KRX regular-market hours 09:00–15:30 · investor flows use the separate bases below
Indices · KOSPI/KOSDAQ open, high, low and close are confirmed regular-session values · Naver Finance daily index data, sourced from KRX
Intraday path · times of KOSPI high/low checked on the 5-minute chart · the chart’s four points are confirmed regular-session values
Investor totals · cited from confirmed regular-session close reporting · KOSPI foreign total -KRW 1.5711tn · retail +KRW 831.9bn · institutions -KRW 903.8bn · other corporations +KRW 1.6430tn · the four categories sum to zero · foreign total is foreign investors -KRW 1.5735tn plus other foreign investors +KRW 2.4bn · other corporations is a separately reported investor category, not a back-solved residual
Stock-level flows · KRX investor trading trends · used only for ranking and concentration direction · not combined with investor totals or converted into shares within the same card
Timing caution · because KRX has after-hours trading, prices, turnover and investor figures shown on ordinary quote screens after 16:00 can mix with the 15:30 regular-session figures · final daily trading details are available after 20:00 · body figures use only confirmed regular-session close series
Program trading · KOSPI arbitrage -KRW 87.0bn · non-arbitrage -KRW 817.5bn · total -KRW 904.5bn · regular-session close basis · KOSPI 200 cash 1,042.46 and futures 1,039.80 excluded from directional judgment because closing times differ
Short selling · regular-market basis · Korea Exchange and Nextrade combined
Industries & themes · close of 46 KRX Index industry indices and 39 theme indices
Individual stock returns · Samsung Electronics, SK hynix, LG Energy Solution, Samsung Life, KB Financial Group, Samsung Electro-Mechanics, Hyundai Motor and Hanwha Aerospace are confirmed closing values · HD Hyundai, HD Korea Shipbuilding & Offshore Engineering, Samsung Heavy Industries and HD Hyundai Heavy Industries cited from regular-session close reporting
Previous domestic session · Sep. 14 Samsung Electronics -4.05% · SK hynix -6.35% based on the Sep. 14 published report
Overseas · Dow, S&P 500, Nasdaq, Philadelphia Semiconductor Index, VIX and U.S. 10-year use Sep. 14 local closes · individual semiconductor returns, the 10-year intraday 5.012% and its move back above 5.02% in Asian trading are from cited reporting
Oil · Brent $105.68 is the Sep. 14 local close · $107s in Asian trading from cited reporting · WTI $103.06 intraday on Sep. 15 KST
USD/KRW · 1,359.2 is Hana Bank’s 15:30 standard trading rate · previous session 1,347.1
Reporting · Anthropic CEO Dario Amodei’s call to slow development and reports of Sam Altman and Elon Musk agreeing, U.S. DOT criticism of Ford–CATL cooperation, fed funds 25bp hike probability in the 90% range, and Daishin Securities comments are all from cited reporting and have not been finalized as policy
Companies · HD Hyundai Heavy Industries metalworkers’ union strike schedule and wage/CBA terms cited from Sep. 15 reporting · Samsung SDI target-price increase from KRW 600,000 to KRW 730,000, SK Innovation KRW 200,000, and POSCO Future M KRW 290,000 maintained, all cited from Sep. 15 brokerage-report coverage
Buybacks · scheduled end dates of Nov. 21 for Samsung Electronics and Nov. 19 for SK hynix cited from Sep. 13 reporting
Calendar · Fed Sep. 15–16 local-time meeting · Bank of England Sep. 17 · Bank of Japan Sep. 17–18 meeting