The Index Recovered 4% From Its Low, Yet Only Four in Ten Stocks Rose
KOSPI +0.46% · down as much as -3.55% intraday, then closing essentially at the high
The primary catalyst was a U.S. rate outlook that shifted toward a September hike after Jackson Hole; renewed U.S.-Iran military conflict over the weekend deepened the opening declineThe rebound from the low was driven less by individuals, foreigners or institutions than by Other Corporations; the share of advancing KOSPI stocks was just 40.2%, down 30.2pp from the previous session's 70.4%
A recovered index is not the same as a recovered market.
KOSPI
6,820.02
+0.46%
KOSDAQ
834.29
-0.49%
MARKET PATH / 01
The Low Came in the Opening Five Minutes; Direction Firmed in the Afternoon
When the direction changed — and what was working then
KOSPI · 09:00—15:306,613.58 gap-down open → 6,547.76 low just after the open → rebound to around 6,690 in the 09:30s → rise after 13:30 → 6,820.02 close
OPEN6,613.58-2.58%
HIGH6,820.10+0.46%
LOW6,547.76-3.55%
CLOSE6,820.02+0.46%
THE READ
The gap-down was Korea repricing weekend developments before much of the world had opened — more a question of sequencing than sheer magnitude. The low arrived in the first five-minute bar, showing that selling did not persist for long. Morning rebounds were pushed back twice; after 13:30 the direction became much more one-sided. The close was effectively the high, but this was still hard to call a broad market advance.
OPEN · MORNING
The low was made immediately after the open
Opened at 6,613.58, 175.30 points below the prior closeLow 6,547.76 immediately after the openRebounded to around 6,690 in the 09:30s, then slipped back toward 6,620 around 10:30One round each of low confirmation and rebound
AFTERNOON
Direction firmed after 13:30
Rose again toward 6,700 after 11:30, then eased to around 6,660 near noonAfter 13:30 the direction firmed; around 6,790 near 14:00Pullbacks were smaller than in the morning
CLOSE
The index finished almost exactly at the high
Based around 6,770 near 14:30, then rose again into the closeRecovered 272.26 points from the low to 6,820.02 · +4.16% from the low · just 0.08 points below the highReturned to a gain after the previous session's decline
Path based on KRX five-minute KOSPI bars. Open, high, low and close are confirmed values; intermediate levels are approximate readings from five-minute bars.
WHY / 02
What Pressured the Index · What Brought It Back
Only the catalysts that actually explained the day's direction
01
The main gap-down catalyst was a U.S. rate outlook that shifted toward a September hike after Jackson Hole
In the Aug. 28 Jackson Hole keynote, Kevin Warsh said inflation should be the Fed's top priority; the market-implied probability of a September hike moved above 50% in one day. In the same U.S. session, SOX fell -3.47%, weighing on the Korean mega-cap semiconductor open.
57.5% · September hike probability · Aug. 28 U.S. close
View evidence
Warsh: inflation should be the Fed's top priority
September hike probability 35.4% → 57.5% · hold 42.4% · Sept. 15–16 FOMC
NVIDIA -4.6% despite strong results in the previous session
Just after the Korean open · Samsung Electronics -3.89% · SK hynix -3.93%
02
Renewed U.S.-Iran military clashes over the weekend deepened the selloff
On Aug. 30 local time, the U.S. struck rocket launchers on Iran's Larak Island; Iran responded with missiles at a U.S. base in Jordan. Korea was the first regular session to absorb the news, making the opening gap larger than rates alone would explain.
+1.38%WTI October futures · Aug. 31 08:49
View evidence
CENTCOM said it struck launchers after detecting an attempt to fire mine-carrying rockets into the Strait of Hormuz
Iranian missiles were intercepted · no major damage reported
Nasdaq-100 futures -0.45% · S&P 500 futures -0.30% · Dow futures -0.21% at the same time
Local assessment: 6–8mn bpd of oil transit remained intact, limiting the probability of an oil-price spike
03
The rebound was helped by easing yield pressure and a firmer won
The rise in U.S. Treasury yields steadied during the morning. The 15:30 USD/KRW reference rate fell KRW 4.00 to 1,368.50, removing one of the pressures that had hit the open. The force that actually lifted the index from the low, however, was flows rather than catalysts — detailed in MONEY.
-KRW 4.00USD/KRW 15:30 reference rate · 1,368.50
View evidence
USD/KRW 1,368.50 vs. 1,372.50 in the previous session
Closing commentary framed recent semiconductor weakness as elevated expectations and flow pressure rather than fundamental impairment
Sept. 1 Korea August exports are a next-session check, not a cause of today's rebound
MONEY / 03
Three Sold; Other Corporations in Two Mega Caps Filled the Gap
The buyers that actually moved today's index
SAMSUNG + SK HYNIX · OTHER CORPORATIONS
+KRW 1.5454tn
Individuals, foreigners and institutions together net sold KRW 1.5773tn of KOSPI cash equitiesIn Samsung Electronics and SK hynix alone, net bought KRW 1.5454tnThat two-stock buying was roughly 98% of the three groups' combined net selling · the two stocks closed +1.17% and +1.27%, forming the practical backbone of the index reboundClosing commentary cited treasury-share purchases by both companies as an important backdrop; this report does not assume that every Other Corporations trade was a buyback
Samsung Electronics · Other Corporations+KRW 509.7bn
SK hynix · Other Corporations+KRW 1.0357tn
Futures · programs · detailed flows
Foreign +KRW 361.0bn
Institution K200 futures+KRW 33.0bn
KOSPI program-KRW 371.6bn
-KRW 273.2bn
Cross-check · KRW 144.3bn individual + KRW 639.9bn foreign + KRW 793.1bn institutional = KRW 1.5773tn · equal to total Other Corporations net buyingOther Corporations by stock · Samsung Electronics +KRW 509.7bn · SK hynix +KRW 1.0357tn · combined +KRW 1.5454tnThe 98% denominator is the KRW 1.5773tn aggregate KOSPI net selling by individuals, foreigners and institutions. The opposite side also includes Other Foreigners and government/local-government accounts; the numerator is Other Corporations net buying in the two stocksLG Innotek +5.07% · close KRW 642,000 · MSCI Korea re-entry takes effect after the close · estimated passive buying KRW 313–439bn (Samsung Securities, Eugene Investment & Securities) · a case where mechanical index demand was reflected in priceVs. prior session · non-arbitrage program selling narrowed from -KRW 1.5403tn to -KRW 273.2bn · foreign K200 futures +KRW 614.0bn → +KRW 361.0bn · arbitrage program -KRW 98.4bnBasis -4.00 · · spot 1,071.85 · futures 1,067.85 (Sep. 2026 contract) · reversed from +2.30 contango in the previous sessionCash and futures have different closing times, so the closing spread is not used here as directional evidenceForeign sell concentration · top 1 24%, top 5 40% / buy concentration · top 1 8%, top 5 28% · institution sell concentration · top 1 35%, top 5 70% / buy concentration · top 1 10%, top 5 28%KOSDAQ · individual +KRW 253.5bn · institution -KRW 201.5bn · foreign -KRW 54.3bnFive-session cumulative (Aug. 25–31) KOSPI · foreign -KRW 5.29tn · individual -KRW 2.83tn · institution +KRW 134.0bnFive-session cumulative K200 futures · foreign +KRW 3.50tn · institution -KRW 3.20tn · individual -KRW 207.0bnTurnover · KOSPI KRW 26.04tn (111% of five-day average; 97% of 20-day average) · KOSDAQ KRW 5.29tn (110%; 89%) · KOSPI KRW 1.70tn · 5.1% of turnover
SECTOR / 04
Where Strength Held · Where It Broke
Today's distribution of strength, not just a ranking
The index was lifted mainly by two pillars: Electrical & Electronics and Chemicals.Only 6 of the 25 KOSPI industry indexes advanced; the other 19 fell on a day when the headline index roseThe weakest group — Construction, Machinery & Equipment and Metals — contained many power-infrastructure and nuclear names · Doosan Enerbility -6.46% · KRX-Akros AI Power Infrastructure -3.20%Defense was also weak · KRX K-AI Defense TOP5+ -3.31% · Hanwha Aerospace -4.75% despite the Spain K9 disclosure · detailed in CATALYSTThe strength in Chemicals included ESS · KRX K-AI Secondary Battery +3.64% · all 10 constituents advanced · SK Innovation +7.36% · detailed in CATALYSTOne session is not enough to call a leadership rotation; persistence and flows remain unconfirmed
STRONG
Electrical & Electronics+1.22%
Chemicals+1.09%
Manufacturing+0.77%
WEAK
Construction-3.85%
Machinery & Equipment-3.56%
Metals-3.39%
Sector evidence
The six lines above are all KOSPI industry indexes · KOSPI: 6 up / 19 down among 25 · KOSDAQ: 7 up / 14 down among 21All KOSPI gainers · Electrical & Electronics +1.22% · Chemicals +1.09% · Manufacturing +0.77% · Real Estate +0.54% · Distribution +0.50% · Pharmaceuticals +0.31%Weak KOSPI groups · Construction -3.85% · Machinery & Equipment -3.56% · Metals -3.39% · Communications -2.96% · General Services -2.80% · Insurance -2.28% · Electricity & Gas -1.70% · Securities -1.66%KOSDAQ strong · Non-Metals +2.31% · Paper & Wood +1.38% · Electrical & Electronics +0.84%KOSDAQ weak · Pharmaceuticals -2.49% · General Services -2.08% · IT Services -1.40% are a separate series · 19 up / 20 down among 39 official KRX theme indexesStrong themes · K-AI Secondary Battery +3.64% (all 10 constituents up) · EV Top 15 +1.86% · K-AI Semiconductor TOP2+ +1.76% · Semiconductor Top 15 +1.07%Weak themes · K-AI Defense TOP5+ -3.31% · Technology Transfer Bio -3.23% (all 15 down) · AI Power Infrastructure -3.20% · Shipbuilding TOP10 -1.47% (all 10 down)Top 10 by market cap · 8 up / 2 down · Samsung Electro-Mechanics +2.60% · LG Energy Solution +2.16% · Samsung Biologics +2.15% · SK hynix +1.27% · Samsung Electronics +1.17% / Samsung Life -1.29% · Samsung Electronics Preferred -0.16%Samsung Electro-Mechanics +2.60% · outlook that Q4 MLCC price increases would broaden to OEM/ODM and finished-product manufacturers · general-purpose X5R +25–30% · AI-server X6S +10–20%Evidence of index weighting · KOSPI Manufacturing +0.77%, yet 232 of 557 stocks rose and 273 fell · Electrical & Electronics +1.22%, yet 46 of 84 rose and 29 fell · KOSPI: limit-up 0 · up 366 · unchanged 54 · down 489 · limit-down 1 · advancer ratio 40.2%KOSDAQ breadth · limit-up 8 · up 741 · unchanged 105 · down 889 · limit-down 0 · 43.0% · numerator is advancers plus limit-up; denominator includes unchanged stocksIndustry returns are market-cap-weighted index returns, not net money flowing into each industry
CHANGE / 05
The Answer to Yesterday's Question
Carrying yesterday's test conditions forward
YESTERDAY → TODAY
The previous session's question was whether the broader semiconductor-tariff review would gain substance. No answer arrived today; the catalysts moving the market shifted to rates and the Middle EastThe tariff-driven losses were reversed, but the advance was narrow. For a third straight session, the index and the share of advancing stocks pointed in different directions
01
Mega-cap semiconductor · Samsung Electronics
-3.38%
→
+1.17%
02
Foreign net selling of SK hynix
-KRW 1.2085tn
→
-KRW 338.2bn
03
KOSPI advancer ratio
70.4%
→
40.2%
CATALYST / 06
K9's First Western European Export — The Market Priced It the Other Way
A single event that received an observable price reaction today
Hanwha Aerospace · Aug. 31 10:29 · single sales/supply contract disclosure
-4.75%
Export implementation contract for K9 self-propelled howitzers with Spain's INDRA SISTEMAS
WHAT · DECISION
Export implementation contract with Spanish defense company INDRA SISTEMAS for K9 self-propelled howitzersContract start Aug. 28 · contract value and end date undisclosed for business-confidentiality reasons · deadline Nov. 28, 2026
TERMS · TRANSACTION
Advance payment · 20% after the first contract is signed · second 5% by Dec. 31, 2026The July 24 framework agreement used a threshold of at least 2.5% of latest sales · applied to 2025 consolidated sales of KRW 26.7029tn, that implies at least KRW 667.6bn · an estimate derived from the threshold, not a disclosed contract value
SHAREHOLDER · INTERPRETATION
K9 export/adoption countries expand to 11 · the first move into Western Europe from an export base centered on Eastern EuropeBecause the contract value is undisclosed, the scale of earnings contribution cannot be fixed until the disclosure-deferral deadlineThe positive filing did not overcome broad weakness in defense stocks that day
MARKET · REACTION
The decline persisted after the 10:29 filing · close -4.75%KRX K-AI Defense TOP5+ -3.31% · 2 of 10 constituents up, 8 downIndividual +KRW 35.2bn net buy / foreign -KRW 21.8bn · institution -KRW 13.4bn net sell
Disclosure schedule
Contract start · Aug. 28, 2026Contract end date · undisclosedDisclosure-deferral deadline · Nov. 28, 2026Second advance-payment deadline · Dec. 31, 2026
CATALYST / 07
U.S. ESS 9GWh — This Contract Came With a Price
A single event that received an observable price reaction today
SK Innovation · subsidiary SK On · disclosed before the Aug. 31 open
+7.36%
SK On Signs Long-Term LFP Supply Deal for ESS with U.S. NeoVolta Power
WHAT · DECISION
Long-term supply of pouch cells for ESS to U.S. energy-storage-system manufacturer NeoVolta PowerConfirmed supply 9GWh · five years from 2027 through 2031 · production at the Georgia plant in the U.S.
TERMS · TRANSACTION
Official contract value undisclosed · industry estimate about KRW 1.5tn · an estimate, not a disclosed amountOnly 9GWh is confirmed · another 9GWh is at the stage of pursuing a separate contract within the year and is not firm volume
SHAREHOLDER · INTERPRETATION
The deal can redirect U.S. local capacity from an EV-heavy production mix toward ESS and help lift utilizationThe confirmed volume is meaningful against SK On's stated 20GWh global ESS new-order target for this yearDeliveries start in 2027, so earnings recognition is still ahead
MARKET · REACTION
Close KRW 125,500 · +7.36% · far above KOSPI +0.46%The full gain is not attributed to this contract alone · the reaction also included a rebound from weakness following the announced SKIET absorption mergerForeign +KRW 18.2bn · institution +KRW 36.6bn net buy / individual -KRW 53.1bn net sell
Contract details · secondary variables
Customer · ESS manufacturer in Pendergrass, Georgia, U.S.Additional cooperation 9GWh · separate contract under pursuit within the year · total cooperation would reach 18GWh if completedSK On North American production capacity · 102GWhSecondary variable · the rise in international oil prices following Middle East clashes was also favorable for the refining business · WTI October futures +1.38% as of Aug. 31 08:49
NEXT / 08
What to Check Next Session
Observable conditions, not probabilities
Can the index hold if Other Corporations buying fades?
A test of how dependent today's rebound was on treasury-share-related demand · compare the next session's change in Other Corporations net buying with the sign of the KOSPI return
Does semiconductor export growth hold in the Sept. 1 preliminary August trade data?
A test of the premise behind the mega-cap semiconductor rebound · check semiconductor export growth in the Korea Customs Service preliminary August trade release at 09:00
Do the index and the advancer ratio point in the same direction again?
They have diverged for three straight sessions since Aug. 27 · count them as aligned when the sign of the KOSPI return and the 50% line for the advancer ratio point to the same side
A day when one buyer absorbed what three sold — and only the index made it all the way back.
Sources · Data Basis
Basis date · Aug. 31, 2026 · KOSPI and KOSDAQ confirmed at the close
Index open/high/low/close · market breadth · turnover · investor totals (individual, foreign, institution, Other Corporations) · program trading · basis · short selling · KRX close-confirmed data and Naver Finance
Intraday path · KRX KOSPI five-minute bars
Stock-level flows · KRX closing investor trading trends · collected Aug. 31
Industries · KRX Index industry indexes, 46 total (KOSPI 25 · KOSDAQ 21) · Aug. 31 close
Themes · 39 official KRX theme indexes · Aug. 31 close · separate series from industries
FX · USD/KRW 15:30 reference rate
Overseas · confirmed Aug. 28 U.S. regular-session close · Dow, S&P 500, Nasdaq, Philadelphia Semiconductor Index · U.S. Treasury 2Y and 10Y · CME FedWatch September rate probability
Commodities · overseas futures · WTI October · Brent December · U.S. equity-index futures · as of Aug. 31 08:49
Company disclosure · Hanwha Aerospace single sales/supply contract, Aug. 31 10:29 · contract value and end date undisclosed · the estimated amount in the body converts the July 24 framework agreement's 2.5%-of-sales threshold using 2025 consolidated sales
SK On U.S. ESS supply contract · confirmed 9GWh · 2027–2031 · official contract value undisclosed · KRW 1.5tn is an industry estimate · additional 9GWh is at the pursuit stage
Other Corporations stock-level flows · KRX investor trading trends · the 98% denominator is aggregate KOSPI net selling by individuals, foreigners and institutions
Reporting · Kevin Warsh Fed Chair keynote at Jackson Hole, Aug. 28 local time · U.S.-Iran military clashes, Aug. 30 local time, per U.S. CENTCOM · Korean opening and closing market reports
Schedule · MSCI Korea August review effective after Aug. 31 close · Korea Customs preliminary August trade at Sept. 1 09:00 · Ministry of Trade, Industry and Energy August trade trends at Sept. 1 11:00 · U.S. August ISM and employment report · U.S. Labor Day holiday Sept. 7
