KOSDAQ Surges Over 5% as AI and Renewable Plays Ignite Rally

The KOSPI slipped 1.45% to 6,166.79, but the KOSDAQ soared 5.01% to 774.30, highlighting a sharp divergence in market sentiment. The session was driven by a powerful rally in renewable energy, AI infrastructure, and select construction names, overshadowing broader index weakness.

SK eternix (475150) +22.02%

SK eternix surged 22.02%, driven by strong sector momentum in renewable energy and energy storage systems (ESS). The rally was fueled by growing policy expectations for solar energy, which lifted the entire sector [3], and a broader anticipation of growth in the renewables and ESS markets [1][4]. Some investors also viewed the stock's recent pullback as a low-point buying opportunity, attracting additional inflows [6]. The stock carries a high debt ratio of 419.7%.

SKTelecom (017670) +10.49%

SKTelecom jumped 10.49% after news emerged that its proprietary AI foundation model, known as 'Dokpamo', has entered a second evaluation phase [7][8]. This development spurred significant investor interest. The rally was further supported by expectations that the company will benefit from government AI projects [9] and positive sentiment ahead of its upcoming earnings release [7]. The stock trades at a P/E of 47.45 with a modest ROE of 2.92%.

GnCenergy Co., Ltd. (119850) +24.05%

GnCenergy soared 24.05% after securing a significant 75.5 billion KRW contract with KT to supply emergency power generators for a data center [12][13]. This deal reinforces the company's growth narrative tied to the expansion of AI data centers (AIDC), which is expected to drive further orders [11]. The rally was also propelled by concentrated buying from foreign and institutional investors [16]. The company shows a solid ROE of 19.71% and a manageable debt ratio of 63.99%.

OCI Holdings Company Ltd. (010060) +15.03%

OCI Holdings gained 15.03% after a regulatory filing disclosed a change in the stake held by its largest shareholder, sparking expectations of a potential shift in the company's governance structure [17]. The disclosure stimulated investor sentiment and triggered buying interest during the session [17]. Details of the specific stake change and its full implications remain unconfirmed based on available headlines. The company is currently unprofitable, with a negative P/E of -47.25 and an ROE of -2.2%.

GS Engineering & Construction Corp (006360) +14.43%

GS E&C rallied 14.43%, rebounding sharply. The move was linked to renewed optimism over its involvement in the massive 12 trillion won East Sea data center project, which is seen as a catalyst for a re-rating of the stock [22]. The stock also moved in sympathy with a broader rally in nuclear power-related construction stocks, triggered by issues in the U.S. nuclear sector [20]. This surge follows a recent 22% drop after disappointing second-quarter results, though the rebound's direct link to earnings is unconfirmed [21].

Sources

1. SK이터닉스, 신재생에너지 성장 기대감…주가 재도약 가능성은 — 증권일보 · 2026-08-04
2. SK이터닉스 주가, 8월 4일 장중 54,700원 17.51% 상승 — 톱스타뉴스 · 2026-08-04
3. [특징주] 정책 기대에 태양광주 강세…SK이터닉스 18% 급등 - 조선비즈 — Chosunbiz · 2026-08-04
4. [특징주] SK이터닉스, 신재생·ESS 성장 기대감에 장중 강세 : 기업주식정보 — 재경일보 · 2026-08-03
5. SK이터닉스 주가 털썩…코스피 5% 가까이 급락, 양대지수 혼조 흐름 — CBC뉴스 · 2026-08-03
6. SK이터닉스(475150)저점에선 물량 모아둘 기회로 보이며 이후 전망 및 대응전략. — 씽크풀 AI · 2026-08-04
7. SK텔레콤 주가 장중 10%대 상승, 독자AI파운데이션모델·실적발표 기대감 반영 — 비즈니스포스트 · 2026-08-04
8. [특징주] SK텔레콤, '독파모' 2차 평가 돌입.. 9%대 '강세' — 글로벌이코노믹 · 2026-08-04
9. SK텔레콤, 정부 AI 프로젝트 기대감에 10% 급등세 — 2news.co.kr · 2026-08-04
10. SK텔레콤 주가 상승 중 — 아시아뉴스통신 · 2026-08-04
11. [종목 포커스] 지엔씨에너지, AIDC 대형화로 수주 확대…2027년 성장 재가속? — 데일리인베스트 · 2026-08-02
12. [공시 Pick] 지엔씨에너지, KT와 755억원 데이터센터 계약… 15%대 급등 — 뉴스투데이 · 2026-08-03
13. 지엔씨에너지, 군산 AI 데이터센터에 755억원 비상발전기 공급…주가도 14%대 '껑충' — 핀포인트뉴스 · 2026-08-03
14. 지엔씨에너지, KT 데이터센터 공급계약에 17%대 강세 — 매일신문 · 2026-08-03
15. [공시 Pick] 지엔씨에너지, 데이터센터 발전기 수주 릴레이에 20%대 주가 급등 — 뉴스투데이 · 2026-08-04
16. [특징주] 외인·기관, 삼성전자·대우건설 매도… 알트·지엔씨에너지 ' 픽' — 뉴스티앤티 · 2026-08-03
17. [특징주] OCI홀딩스, 최대주주 지분 변동 공시에 장중 강세…지배구조 변화 기대감 : 기업주식정보 — 재경일보 · 2026-08-03
18. OCI홀딩스 투자분석 2026. 08. 01 — 주달 · 2026-08-01
19. 2분기 부진 GS건설…주가 향방은 AI데이터센터에[주末머니] — v.daum.net · 2026-08-02
20. 美 원전 이슈?...GS건설·DL이앤씨·대우건설·원전주 '장중 급등' — 초이스경제 · 2026-08-04
21. [베스트&워스트] 2분기 실적에 엇갈린 코스피⋯LG생건 15%↑ㆍGS건설 22%↓ — v.daum.net · 2026-07-31
22. “탄탄한 주택 + 12조 동해 데이터센터 잭팟…GS건설, 확실해진 재평가 신호탄” — newsquest.co.kr · 2026-08-03

This is market commentary, not investment advice.