Ask Warren

Monthly wrap · September 2026 · 20 trading days

KOSPI edges up 0.3% in September, KOSDAQ gains 2.6% as chip names rally on record exports; foreigners sell

KOSPI+0.3%KOSDAQ+2.6%KOSPI 200+0.9%

September was a month of narrow index gains and wide moves beneath the surface. KOSPI rose 0.3% to 6838.0, KOSDAQ rose 2.6% to 855.9 and KOSPI 200 rose 0.9% to 1081.8. The main driver was chips. South Korea's exports jumped 83.5% in September from a year earlier to a record $120.9 billion, beating the median expectation of 62.0%, and chip exports drove the gain. Samsung Electronics rose 3.3% and SK hynix 6.1%. The effect spread outward to chip testing and packaging (up 21.4%) and chip equipment and materials (up 13.1%). Within these, SFA Semicon rose 89.1%, Exicon 104.1%, Hana Micron 33.2% and Intekplus 61.3%.

The second story was the Fed. It raised its policy rate by 0.25 point to 3.75-4.00%, its first hike since July 2023, and left room for further tightening. The Korea-US rate gap widened again and foreign investors sold for several straight sessions, about 11.9 trillion won over six sessions at one point. Banks fell despite hopes of better net interest margins: KB Financial Group fell 2.6% and Shinhan Financial Group 2.6%. Beyond that, biotech, beauty, autos and aesthetics fell sharply, with no clear reason reported for most of those moves.

Why the market moved

Record chip exports of $120.9 billion lifted chip stocks, while a Fed hike to 3.75-4.00% and a jump in US Treasury yields drove foreign selling and kept KOSPI near flat.123

Top themes

Chip testing & packaging

Record chip exports; Samsung DDR5 outsourcing123

  • Exicon, Chip packaging theme leader+104.14%
  • SFA Semicon, About 75% of sales tied to Samsung+89.14%

Semiconductor equipment & materials

Record chip exports lift equipment names123

The big stories

Record chip exports lift Samsung and SK hynix

South Korea's exports jumped 83.5% in September from a year earlier to a record $120.9 billion, beating expectations, and chip exports drove the gain. Samsung Electronics closed up 3.26% and SK hynix up 6.09%, and the market ended higher.123

Directly affected

Next in line

Hawkish Fed hike drives foreign selling in Seoul

The Fed raised its policy rate by 0.25 point to 3.75–4.00%, its first hike since July 2023, and signaled possible further tightening. Foreign investors sold roughly 2.2–2.4 trillion won on the day and had sold for six straight sessions totaling about 11.9 trillion won.123

Next in line

SFA Semicon surges on Samsung DDR5 outsourcing

Samsung is shifting its Onyang plant toward HBM, so back-end work for general-purpose memory is moving to outside firms, a brokerage analysis said. SFA Semicon, about 75% of whose sales are tied to Samsung, closed up 89.14% and was reported to be up 23% in four days.1234

Directly affected

Next in line

HLB Pharmaceutical shares surge

HLB Pharmaceutical shares rose sharply on September 28 and 29, with reports saying the stock hit near its daily limit. It closed up 65.53% in the period covered.12

Directly affected

Orum Therapeutics shares plunge

Orum Therapeutics fell sharply after a major management matter was disclosed, dropping 18.4% on September 18 and about 27% intraday on September 21. It closed down 65.92% in the period covered.123

Directly affected

The market

KOSPI rose 0.3% and KOSDAQ 2.6%. Breadth was negative: 1,156 stocks rose and 1,359 fell, with 252 unchanged. Average daily trading value was about ₩28.2 trillion, against a period average of about ₩28.4 trillion. Intramonth swings were large. On September 14 KOSPI fell 3.26% on AI-pace worries and Middle East tension, on September 18 it rose 2.66% to 6894.2, and on September 28 it fell 2.70% to 6889.7 as US Treasury yields jumped; the 30-year yield briefly hit 5.519% during the Chuseok holiday. The won ended at 1358.4 per dollar, up 1.3% against the dollar over the month. The Korean 3-year yield was 4.011%. Foreign investors net sold about ₩21.5 trillion on KOSPI and about ₩1.5 trillion on KOSDAQ. Overseas levels at month-end: S&P 500 7651.5, Brent oil $98.03, gold $4186.7, Nikkei 225 66753.7.

KOSPIDaily closes · shaded: this wrap6,838.04
6,0008,000
Feb 23May 6Jul 20Sep 30
KOSDAQDaily closes · shaded: this wrap855.91
8001,0001,200
Feb 23May 6Jul 20Sep 30

1,156 stocks rose, 1,359 fell · trading value ₩28T

USD/KRW1,358.4−1.3%
KTB 3y4.01+17bp
UST 10y5.29—
S&P 5007,651.54—
Nasdaq 100 (QQQ ETF)—
US chips (SOXX ETF)—
Nikkei 22566,753.72—
Brent oil98.03—
Gold4,186.7—
Copper (CPER ETF)—

Themes investors follow

Chip testing and packaging led at 21.4%, followed by chip equipment and materials at 13.1%, lithium and rare metals at 12.3%, hydrogen at 10.4%, cybersecurity at 10.0% and HBM and AI chips at 9.5%. In HBM, HVM rose 30.3%, Hanmi Semiconductor 16.3% and SK hynix 6.1%. Power grid and cables rose 6.9%, led by Gaon Cable at 50.0% and Iljin Electric at 15.9%. Oil, refining and chemicals rose 6.2%, with SK Innovation up 18.6%. Defense was up 3.7% overall, but Hanwha Aerospace fell 8.6%. Shipbuilding fell 4.4%, with Hanwha Ocean down 10.4% and HD Hyundai Marine Solution up 14.7%. Weak themes were aesthetics and botox (-14.7%), crypto (-12.5%), zinc and non-ferrous metals (-12.0%), casinos (-9.0%), platforms (-7.3%) and K-beauty (-7.0%). Robotics fell 0.7%, AI software 2.5% and EV batteries rose 1.3%. Biotech fell 1.0%; HLB Pharmaceutical rose 65.5%, while Orum Therapeutics fell 65.9%.

Popular themes

Best themes

Worst themes

  • Aesthetics & botox−14.7%Genic −36.6% · Hugel −28.7% · PharmaResearch −27.1%
  • Crypto & digital assets−12.5%Satoshi Holdings −22.4% · Parataxis Ethereum −8.9% · GalaxiaMoneytree −6.1%
  • Zinc & non-ferrous metals−12.0%Daiyang Metal −43.9% · Korea Zinc −16.2% · Kukil Metal −10.4%
  • Casinos−9.0%Lotte Tour Development −13.0% · Kortek −11.5% · Grand Korea Leisure −9.2%
  • Internet platforms−7.3%NHN −26.0% · Mobirix −25.2% · NHN Bugs −17.1%
  • K-beauty−7.0%Silicon 2 −29.6% · Cosmecca Korea −24.0% · APR −21.2%

The biggest companies

SK hynix rose 6.1% to a market value of about ₩1,297 trillion and Samsung Electronics rose 3.3% to about ₩1,570 trillion, helped by the record chip exports; a Yuanta Securities report said the memory cycle may last longer than a slowdown in price gains. SK Square rose 9.8% and Samsung Electro-Mechanics 3.8%, with filings showing substrate capacity expansion and a supply contract. Decliners were Hyundai Motor (-14.5%), KIA (-13.9%), Samsung C&T (-9.3%), Hanwha Aerospace (-8.6%), Samsung Biologics (-8.4%), Samsung Life Insurance (-7.9%), LG Energy Solution (-5.5%), HD Hyundai Heavy Industries (-3.6%), KB Financial Group (-2.6%), Shinhan Financial Group (-2.6%) and Doosan Enerbility (-1.1%). No clear reason was reported for most of these.

Who was buying and selling

Foreign investors were heavy net sellers of SK hynix (about ₩11.6 trillion), Samsung Electronics (about ₩4.9 trillion), Samsung Electronics Preferred (about ₩1.0 trillion) and Doosan Enerbility (about ₩578.4 billion). They bought SK Square (about ₩724.0 billion, up 9.8%), Woori Financial Group (about ₩473.5 billion), Korean Air Lines (about ₩294.4 billion, up 13.9%) and SK Innovation (about ₩293.9 billion, up 18.6%). Institutions bought Samsung Electronics (about ₩3.2 trillion), POSCO International (about ₩1.0 trillion) and Hanmi Semiconductor (about ₩378.9 billion), and sold SK hynix, NAVER and Hyundai Motor. Retail investors bought Hyundai Motor (about ₩648.6 billion, down 14.5%), Doosan Enerbility and Samsung Electronics Preferred, while selling SK hynix (about ₩9.7 trillion) and Samsung Electronics (about ₩8.6 trillion). Sources noted that other corporations, linked to large buybacks by Samsung and SK hynix, bought about ₩1.7 trillion on one day.

Foreign investors

Net bought

  1. 1SK Square+₩724B+9.8%
  2. 2Woori Financial Group+₩474B+3.3%
  3. 3Korean Air Lines+₩294B+13.9%
  4. 4SK Innovation+₩294B+18.6%
  5. 5GS Holdings+₩215B−15.7%
  6. 6PharmaResearch+₩137B−27.1%
  7. 7LS Electric+₩131B−1.2%
  8. 8SFA Semicon+₩122B+89.1%
  9. 9Hyundai Mobis+₩121B−19.1%
  10. 10Robotis+₩111B+11.0%
  11. 11Korea Investment Holdings+₩93B−7.9%
  12. 12Samsung SDS+₩92B−8.7%
  13. 13Gaon Cable+₩83B+50.0%
  14. 14Koh Young Technology+₩80B+8.8%
  15. 15Techwing+₩75B+4.7%

Net sold

  1. 1SK hynix−₩12T+6.1%
  2. 2Samsung Electronics−₩4.9T+3.3%
  3. 3Samsung Electronics Pref.−₩1T+4.7%
  4. 4Doosan Enerbility−₩578B−1.1%
  5. 5Doosan−₩420B+8.3%
  6. 6Netmarble−₩376B−8.8%
  7. 7DB HiTek−₩319B+43.8%
  8. 8Samsung Electro-Mechanics−₩272B+3.8%
  9. 9Hyundai Motor−₩270B−14.5%
  10. 10Shinhan Financial Group−₩269B−2.6%
  11. 11KB Financial Group−₩268B−2.6%
  12. 12Leeno Industrial−₩191B+10.2%
  13. 13HLB−₩183B+16.3%
  14. 14EO Technics−₩168B+28.7%
  15. 15LG Chem−₩158B−10.3%

Institutions

Net bought

  1. 1Samsung Electronics+₩3.2T+3.3%
  2. 2POSCO International+₩1T+5.9%
  3. 3Hanmi Semiconductor+₩379B+16.3%
  4. 4Samsung Electro-Mechanics+₩372B+3.8%
  5. 5Samsung Electronics Pref.+₩357B+4.7%
  6. 6Shinhan Financial Group+₩311B−2.6%
  7. 7KB Financial Group+₩303B−2.6%
  8. 8Doosan+₩242B+8.3%
  9. 9DB HiTek+₩230B+43.8%
  10. 10Jusung Engineering+₩205B+31.3%
  11. 11POSCO DX+₩204B−8.1%
  12. 12SK Innovation+₩198B+18.6%
  13. 13EO Technics+₩196B+28.7%
  14. 14HPSP+₩195B+26.9%
  15. 15Fadu+₩168B+24.3%

Net sold

  1. 1SK hynix−₩653B+6.1%
  2. 2NAVER−₩396B−10.7%
  3. 3Hyundai Motor−₩379B−14.5%
  4. 4Hyundai Mobis−₩316B−19.1%
  5. 5Alteogen−₩274B−17.3%
  6. 6SK Square−₩260B+9.8%
  7. 7APR−₩227B−21.2%
  8. 8Samsung SDI−₩192B−10.8%
  9. 9PharmaResearch−₩172B−27.1%
  10. 10GS Holdings−₩158B−15.7%
  11. 11KIA−₩150B−13.9%
  12. 12Samsung Biologics−₩135B−8.4%
  13. 13Celltrion−₩130B−5.9%
  14. 14L&F−₩129B−23.6%
  15. 15OCI Holdings−₩129B−19.5%

Retail investors

Net bought

  1. 1Hyundai Motor+₩649B−14.5%
  2. 2Doosan Enerbility+₩620B−1.1%
  3. 3Samsung Electronics Pref.+₩599B+4.7%
  4. 4NAVER+₩418B−10.7%
  5. 5Netmarble+₩382B−8.8%
  6. 6Alteogen+₩314B−17.3%
  7. 7Samsung SDI+₩302B−10.8%
  8. 8HLB+₩216B+16.3%
  9. 9APR+₩203B−21.2%
  10. 10Hyundai Mobis+₩191B−19.1%
  11. 11LG Innotek+₩181B−12.1%
  12. 12Hanwha Ocean+₩173B−10.4%
  13. 13L&F+₩168B−23.6%
  14. 14Daewoo Engineering & Construction+₩165B−2.5%
  15. 15Doosan+₩161B+8.3%

Net sold

  1. 1SK hynix−₩9.7T+6.1%
  2. 2Samsung Electronics−₩8.6T+3.3%
  3. 3SK Innovation−₩488B+18.6%
  4. 4SK Square−₩461B+9.8%
  5. 5Korean Air Lines−₩376B+13.9%
  6. 6Hanmi Semiconductor−₩294B+16.3%
  7. 7Jusung Engineering−₩274B+31.3%
  8. 8HPSP−₩232B+26.9%
  9. 9LG Electronics−₩211B−1.9%
  10. 10Robotis−₩150B+11.0%
  11. 11Gaon Cable−₩138B+50.0%
  12. 12DL E&C−₩137B+8.1%
  13. 13Samsung Electro-Mechanics−₩118B+3.8%
  14. 14S-Oil−₩114B+7.7%
  15. 15Tesco−₩90B+17.7%

ETFs

Semiconductor ETFs led: DS KOSDAQ Active rose 23.0%, SOL Semiconductor Front-End Process 22.1%, KODEX US CPU Semiconductor TOP10 20.9%, HANARO Semiconductor Core Process Leaders 19.4% and SOL AI Semiconductor Materials & Parts 18.3%. TIGER Semiconductor rose 14.8% and KODEX Semiconductor 14.4%. The weakest were cosmetics, bio, auto and robotics funds: SOL Cosmetics TOP3 Plus fell 18.3%, TIGER Cosmetics 16.8%, TIME K Bio Active 15.3%, TIGER KOSDAQ 150 Biotech 14.3%, KODEX Automobiles 11.8% and TIGER China Humanoid Robot 10.3%. Money followed chips and left beauty, bio and autos.

Best ETFs

Worst ETFs

Leveraged and inverse ETFs are left out; moves are the daily moves compounded.

How our signals did

There were no Squeeze! setups this month. Technical signals produced 40 events, of which 12 worked. Winners included SM Bexel (breakout, +35.2%), Uniquest Coporation (golden cross, +20.7%), DI (breakout, +17.3%) and LS Eco Energy (breakout, +3.4%). Failures included The Codi (-59.2%), KEPCO Engineering & Construction (-32.3%), Hyundai Bioland (-22.3%), Hana Micron (-17.6%), Korean Air Lines (-15.8%) and Lightron Fiber-Optic Devices (-7.0%). No pair trades were flagged. Short squeeze scores were 60 for Meritz Financial Group, Hanssem and ISU Specialty Chemical, 58 for SM Entertainment and KMW. Nine IPOs listed, including Wise Planet Company (+285.8% on day one), Neosapience (+243.0%) and Sky Labs (+135.0%).

Notable technical signals

40 notable signals: 12 moved the way they pointed so far.

Highest short squeeze scores

Signals describe past prices. Results run from the signal to the latest close; they are not recommendations.

Written by AI from JONBUR's data and checked against those figures. Index and stock moves are the daily moves compounded over the period. Reasons come only from the linked daily wraps, news, filings and broker reports; when none gives a reason, we say so. Not financial advice.

All monthly wraps →