KOSPI Falls 2.70% as HLB, Solar and AI Cooling Resist the Selloff

South Korean equities reopened after Chuseok with a sharp split: the KOSPI lost 2.70% to 6,889.74, while the KOSDAQ edged up 0.25% to 846.58 on September 28, 2026. The latter was not a convincing signal of broad risk appetite. It finished well below its intraday high of 861.15, and the KOSPI closed almost at its session low. [1] [2] [3] [4]

Selective demand survived a weak benchmark

A 12:01 p.m. market report showed Samsung Electronics and SK hynix down around 4%, with foreigners and institutions selling KOSPI shares and individuals buying. Those observations describe the midday session, not final investor flows. Verified closing breadth and final flow totals were unavailable, so neither is estimated here. [11]

KSI reads the session as selective demand for identifiable business catalysts rather than a broad recovery. Three pockets stood out: a regulatory milestone in oncology, solar pricing expectations and access to AI data-center customers. Their resilience does not prove that the same money leaving memory chips entered these shares. Price divergence is evidence of different investor priorities, not a complete map of capital flows.

HLB: regulatory progress becomes a commercial test

HLB (028300) closed at KRW 39,700, up 29.95%. The FDA announced September 23 approval of lirafugratinib for previously treated unresectable, locally advanced or metastatic cholangiocarcinoma with FGFR2 gene fusions or rearrangements. This is a defined indication, not a blanket approval covering liver cancers. [5] [8]

The investment question now moves toward commercialization. Approval removes an important barrier, but prescriptions, reimbursement, launch spending and eventual cash generation determine economic value. Affiliates should not automatically be assigned the same benefit. Follow-up disclosures matter more than extrapolating a limit-up move into an earnings forecast.

Solar: stronger pricing needs to reach margins

Hanwha Solutions (009830) gained 15.07% to KRW 33,600 in the daily price record. Newsis linked the sector’s strength to higher US solar-module and polysilicon prices and supply uncertainty that could favor local producers. [6] [10]

KSI interprets this as a repricing of potential profitability, with execution still open. Input costs, utilization and the timing of contract repricing can interrupt the path from stronger product prices to operating income. The next useful evidence is company guidance on volumes and margins; another strong share-price session would not settle those questions.

AI cooling: customer access is different from orders

LG Electronics (066570) rose 2.63% to KRW 214,500. Its September 28 announcement confirmed selection the previous day as a power-and-cooling partner in the NVIDIA Partner Network. This expands opportunities to present cooling solutions to AI infrastructure customers. [7] [9]

The designation does not establish a contract value or guarantee sales. The commercial test is whether qualification and customer access convert into project adoption. Cooling strength alongside weak chip bellwethers illustrates differentiation within AI spending, although one session cannot establish a durable leadership change.

What would improve the next session?

Watch whether the KOSPI can regain 6,900 and absorb supply toward 7,000, whether chip selling moderates, and whether the KOSDAQ retains gains into the close. A recovery involving more industries would be more persuasive than another isolated rally. For the three Focus themes, track commercialization, margin conversion and actual project awards respectively. Index and stock figures above refer to September 28 regular-session daily closing records; intraday flow observations are explicitly time-stamped.

Sources

1. Investing.com — KOSPI historical data
2. Investing.com — KOSDAQ historical data
3. 한스경제·아주경제 — 코스피 2.70% 내린 6889.74 마감
4. 연합뉴스 — 코스닥 846.58 장종료
5. Investing.com — HLB historical data
6. Investing.com — Hanwha Solutions historical data
7. Investing.com — LG Electronics historical data
8. FDA — Oncology approval notifications: lirafugratinib, September 23
9. LG — AI 데이터센터 냉각솔루션 분야 엔비디아 공식 파트너 됐다
10. 뉴시스 — 미국 태양광 가격 상승에 수혜 기대감
11. 조선비즈 — 삼전닉스 4%대 하락세에 코스피 2% 하락 중

Key Data Sources

• Investing.com — KOSPI historical data
• Investing.com — KOSDAQ historical data
• 한스경제·아주경제 — 코스피 2.70% 내린 6889.74 마감
• 연합뉴스 — 코스닥 846.58 장종료
• Investing.com — HLB historical data
• Investing.com — Hanwha Solutions historical data
• Investing.com — LG Electronics historical data
• FDA — Oncology approval notifications: lirafugratinib, September 23
• LG — AI 데이터센터 냉각솔루션 분야 엔비디아 공식 파트너 됐다
• 뉴시스 — 미국 태양광 가격 상승에 수혜 기대감
• 조선비즈 — 삼전닉스 4%대 하락세에 코스피 2% 하락 중