The South Korean stock market experienced a severe downturn on July 28, 2026, with the benchmark KOSPI plummeting 10.84% to close at 6,023.66 and the tech-heavy KOSDAQ dropping 7.72% to 705.85. Foreign investors heavily sold off KOSPI shares, registering a massive net-sell of 4,966,558 million KRW, while the USD/KRW exchange rate finished at 1,459.60.

SAMSUNG BIOLOGICS (207940) +0.26%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
58.29	9.61	26,572	₩71.7T	19.56%	51.40%	982,000–1,987,000

Samsung Biologics edged up 0.26% amid mixed market signals. The stock benefited from strong expectations that its growth will accelerate in earnest starting from the third quarter [2]. However, this positive sentiment was tempered as analysts simultaneously lowered the company's target price [2]. While the stock recently turned upward over five consecutive trading days [1] and experienced intraday gains [4], the specific drivers behind these movements and the details of recent pharmaceutical disclosures [3] remain unconfirmed from the available headlines.

LIG Defense&Aerospace (079550) +0.14%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
60.52	10.65	11,516	₩15.3T	22.47%	440.12%	360,000–1,118,000

LIG Defense&Aerospace managed a slight gain of 0.14% despite experiencing high volatility. The company announced a large-scale contract, which typically serves as a strong positive catalyst [5]. However, despite this favorable news, the stock suffered a sharp intraday plunge of over 7% [5]. The exact underlying reasons and background for this sudden intraday drop despite the major contract win remain unconfirmed from the provided headlines.

Peptron, Inc. (087010) +10.94%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
-143	21.83	-1,000	₩3.3T	-23.46%	11.33%	98,000–392,500

Peptron surged 10.94% on the KOSDAQ, driven by multiple factors. Foreign investors actively net-purchased Peptron shares [7], providing strong upward momentum. Additionally, the stock benefited from a broader positive market trend as both pharmaceutical indices rose in tandem [11]. Although the stock experienced a recent sharp surge [8] and after-hours gains [9], the precise reasons behind these rapid price spikes, as well as its historical recovery from limit-down thresholds [10] or bond repayment burdens [6], remain unconfirmed from the headlines.

Sources

1. 삼성바이오로직스 주가 최근 5거래일 상승세 전환 — 톱스타뉴스 · 2026-07-25
2. 삼성바이오로직스, 3분기부터 성장 본격화 기대...목표주가↓ — ksdaily.co.kr · 2026-07-27
3. [제약공시 책갈피] 7월 4주차 - 삼성바이오로직스·유한양행外 — 메디파나뉴스 · 2026-07-24
4. 삼성바이오로직스 주가, 7월 27일 장중 1,539,000원 1.38% 상승 — 톱스타뉴스 · 2026-07-27
5. [특징주] LIG디펜스앤에어로스페이스, 대규모 계약에도 장중 7%대 급락 : 기업주식정보 — 재경일보 · 2026-07-27
6. 펩트론·코오롱티슈진, 주가 하락에 사채 상환 부담…60%대 괴리 어떻게 메우나 — PRESS9 · 2026-07-27
7. 13일, 외국인 코스닥에서 주성엔지니어링(-4.90%), 펩트론(-3.05%) 등 순매수 — ThinkPool · 2026-07-27
8. [바이오맥짚기] '어닝 서프라이즈' 아이센스 9%↑…펩트론·셀리드도 급등 — 네이트 · 2026-07-28
9. 4일 연속 下 면한 코오롱티슈진…펩트론, 시간외 급등 이유는[바이오 맥짚기] — 네이트 · 2026-07-27
10. HLB와 펩트론이 하한가 맞았을 때 기사회생한 방법 — v.daum.net · 2026-07-27
11. 양 제약지수 동반 상승, 펩트론 13.77% ↑ — 의약뉴스 · 2026-07-27

This is market commentary, not investment advice.