KOSPI and KOSDAQ rally on AI, data‑center and volatility‑indicator triggers

The KOSPI climbed 0.62% to 6,297.46 while the KOSDAQ surged 5.13% to 839.75, reflecting a broad rally across technology and AI‑related names. A stronger USD/KRW at 1,412.20 and recent volatility‑indicator (VI) activations added to the upbeat market tone.

TAIHAN Fiberoptics Co.,LTD (010170) +19.11%

TAIHAN Fiberoptics Co.,LTD chart

Price now₩13,610
Prev close₩11,460
Change+18.76%
Mkt cap₩2.1T
P/E-56.24
P/B27.72
EPS₩-242
ROE-28.75%
Debt ratio116.70%
52W range₩923–31,500

TAIHAN Fiberoptics surged 19.11% as market momentum from the volatility‑indicator (VI) trigger in Daehan Gwangtongshin’s shares spilled over to related tech names. The VI activation caused a buying surge from the opening session on Aug 7 [2], and the company’s own announcement to re‑evaluate AI data‑center order momentum lifted investor expectations on Aug 9 [6]. A brief offset came from foreign investors’ net selling in the KOSDAQ on Aug 6, which had previously pressured the stock lower [5].

Alteogen Inc. (196170) +13.11%

Alteogen Inc. chart

Price now₩345,000
Prev close₩305,000
Change+13.11%
Mkt cap₩18.5T
P/E170.29
P/B54.31
EPS₩2,026
ROE29.86%
Debt ratio42.24%
52W range₩253,000–569,000

Analyst consensus — 3 ratings, last 180 days · avg target ₩476,667

Buy3
Hold0
Sell0

Alteogen jumped 13.11% on strong earnings and institutional backing. Royalty receipts helped lift first‑half operating profit by 37% year‑on‑year, and Q2 profit reached 342 billion KRW, beating forecasts [7][12]. The results triggered a profit‑turn and exceeded expectations, reinforcing confidence after the company overcame a royalty shock and patent dispute [11]. In parallel, BlackRock expanded its stake, signalling renewed institutional trust and adding further upside pressure [9].

AUK (017900) +18.50%

AUK chart

Price now₩9,270
Prev close₩7,810
Change+18.69%
Mkt cap₩537B
P/E126.99
P/B1.94
EPS₩73
ROE2.51%
Debt ratio8.52%
52W range₩1,760–22,450

AUK surged 18.5% as the rally in its peer Gwangjeon (광전자) lifted sector sentiment. Gwangjeon’s shares jumped 17.08% on Aug 7 and 18.05% on Aug 10, with the VI indicator firing twice in the morning, indicating strong buying pressure [13][14][15][16]. Earlier, on Aug 6, foreign and institutional investors sold Gwangjeon, causing a 3%‑plus decline [17], but the broader five‑day streak of consecutive gains in early August underscored a bullish backdrop [18].

MakinaRocks Co., Ltd. (477850) +16.01%

MakinaRocks Co., Ltd. chart

Price now₩33,750
Prev close₩29,050
Change+16.18%
Mkt cap₩599B
P/E-35.75
P/B34.65
EPS₩-944
ROE0.00%
Debt ratio54.82%
52W range₩13,420–83,600

MakinaRocks rose 16% after it disclosed negotiations for AI contracts that could lift sales by roughly 10% versus the prior year, sparking optimism in the AI‑robot niche [20]. The stock had briefly climbed to 30,500 KRW on Aug 6 before slipping on Aug 7 as investors took profits [19][21]. The broader AI‑robot wave, highlighted in market commentary, further reinforced the positive tone despite limited detail on the underlying drivers [22].

SANIL ELECTRIC (062040) +14.43%

SANIL ELECTRIC chart

Price now₩180,300
Prev close₩157,300
Change+14.62%
Mkt cap₩5.5T
P/E36.86
P/B9.36
EPS₩4,891
ROE0.00%
Debt ratio23.09%
52W range₩101,700–341,000

Analyst consensus — 8 ratings, last 180 days · avg target ₩332,750

Buy8
Hold0
Sell0

SANIL Electric leapt 14.4% on expectations of record‑high sales from a surge in data‑center special transformer orders, a trend reported across several outlets [23][25][26]. IBK Securities upgraded its target price by 22%, adding further bullish impetus [24]. The combination of strong order flow and analyst endorsement drove the share price higher, while earlier on Aug 7 the stock had dipped 2.54% intraday, underscoring the recent reversal [28].

Sources

  1. 대한광통신 주가, 8월 7일 장중 11,410원 3.07% 상승 — 톱스타뉴스 · 2026-08-07
  2. [속보] 대한광통신 VI 발동, 주가 장초반부터 급등...양대지수도 '맑음' — cbci.co.kr · 2026-08-10
  3. 대한광통신 주가, 급등세... 왜? — 금강일보 · 2026-08-06
  4. 대한광통신 주가, 8월 6일 장중 11,205원 6.67% 하락 — 톱스타뉴스 · 2026-08-06
  5. 06일, 외국인 코스닥에서 레인보우로보틱스(+1.14%), 대한광통신(-8.29%) 등 순매도 — hankyung.com · 2026-08-06
  6. 대한광통신, 월요일 앞두고 AI데이터센터 수주 모멘텀 재점검 — cbci.co.kr · 2026-08-09
  7. 기술료 들어오는 알테오젠...상반기 영업이익 37%↑ 호실적 — 메디칼타임즈 · 2026-08-07
  8. 알테오젠 주가, 8월 7일 305,000원 3.92% 상승 마감 — 톱스타뉴스 · 2026-08-07
  9. 알테오젠, 호실적·블랙록 지분 확대에 8%↑ — 뉴시스 · 2026-08-10
  10. [Stock Tracking] 알테오젠, '3억 불 딜' 불구 상승은 미약…하반기 '상승장' 견인할까 — 녹색경제신문 · 2026-08-06
  11. 흔들렸던 알테오젠…로열티 쇼크·특허 분쟁 딛고 반등 나선다 — 쿠키뉴스 · 2026-08-07
  12. 알테오젠, 2분기 영업익 342억원…흑자전환·예상치 상회 — 연합인포맥스 · 2026-08-07
  13. 광전자 주가, 8월 7일 장중 7,950원 17.08% 상승 — 톱스타뉴스 · 2026-08-07
  14. 광전자 주가 급등흐름…오전 VI 2회 발동되기도 — cbci.co.kr · 2026-08-07
  15. 광전자 주가, 8월 10일 장중 9,220원 18.05% 상승 — 톱스타뉴스 · 2026-08-10
  16. [서울데이터랩]코스피 거래상위 종목 혼조…혜인 26% 급등, 한화솔루션·광전자 강세 — 서울신문 · 2026-08-07
  17. [마감분석] 광전자, 외국인·기관 동반 매도세 속 3%대 하락 : 한국증시 — 재경일보 · 2026-08-06
  18. 8월 1주차 광전자 주가 5거래일간 급등 마감 — 톱스타뉴스 · 2026-08-08
  19. 마키나락스 주가, 8월 6일 장중 30,500원 2.35% 상승 — 톱스타뉴스 · 2026-08-06
  20. [공시]마키나락스 "매출 대비 10%↑ AI계약 논의” — 한스경제 · 2026-08-07
  21. 마키나락스 주가, 8월 7일 29,050원 대에 큰 폭 하락 마감 — 톱스타뉴스 · 2026-08-07
  22. 공모주 시장도 'AI·로봇' 열풍…코스모로보틱스·마키나락스 두각 — 데일리한국 · 2026-08-08
  23. [특징주] 산일전기, 역대급 매출에 데이터센터 수주 기대감…10%대 강세 — 에너지경제신문 · 2026-08-10
  24. IBK證 산일전기, 데이터센터향 특수변압기 수주 확대…목표주가 22%↑ — 아주경제 · 2026-08-09
  25. 산일전기, AI 전력난 수혜에 분기 최대 실적…'데이터센터 핵심' 특수변압기 수주 '폭증' — 네이트 · 2026-08-09
  26. 산일전기, 실적 앞서는 수주…데이터센터 확장 본격화-유안타 — edaily.co.kr · 2026-08-09
  27. [특징주] 산일전기, 역대 최대 실적·수주 호조에 14%대 급등 — 네이트 · 2026-08-10
  28. 산일전기 주가, 8월 7일 장중 157,300원 2.54% 하락 — 중앙이코노미뉴스 · 2026-08-07

This is market commentary, not investment advice.