KOSPI and KOSDAQ Skyrocket as Semiconductor Giants Stage Massive Rebound

The South Korean stock market experienced an extraordinary rally on July 31, 2026, with the benchmark KOSPI soaring 17.91% to close at 6,595.45 and the KOSDAQ climbing 11.63% to 719.76. Foreign and institutional investors heavily bought into the market, recording net purchases of 7,241,449 million KRW and 1,139,680 million KRW on KOSPI, respectively. This massive influx of capital drove a historic recovery across major technology and semiconductor equities.

SK hynix (000660) +29.95%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
29.14	10	58,955	₩1,255.0T	61.16%	35.56%	245,000–2,987,000

SK hynix surged 29.95% on July 31, recovering from a sharp two-day drop earlier in the week [1]. While foreign media warned that recent declines were just the "tip of the iceberg" amid AI bubble concerns [2], several positive drivers reversed the trend. SK Group Chairman Chey Tae-won purchased 4.8 billion KRW worth of shares on the open market to demonstrate responsible management [5]. Additionally, Korea Investment & Securities issued an optimistic target price of 4.7 million KRW [3][4], and SK hynix ranked first in overseas ADR net purchases [6], boosting investor sentiment.

SamsungElectronics (005930) +26.81%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
39.99	4.1	6,564	₩1,534.6T	19.16%	30.15%	67,500–374,500

Samsung Electronics jumped 26.81% on July 31. The stock had previously suffered from AI bubble anxieties [10] and fell sharply alongside SK hynix over a two-day period [7][11]. While the company recorded strong earnings exceeding 89 trillion KRW, its stock had remained sluggish for unconfirmed detailed reasons [12]. However, expectations of record-high dividend payouts served as a defensive shield [9]. The stock experienced a sharp rally on July 30 [8], although the specific drivers for that day's jump remain unconfirmed.

SKSQUARE (402340) +29.91%

P/E	P/B	EPS	Mkt Cap	ROE	Debt Ratio	52W Range
15.62	4.95	66,468	₩137.0T	55.09%	7.50%	130,900–2,189,000

SK Square hit the daily upper limit, rising 29.91% on July 31. The stock's massive surge was primarily driven by a recovery in semiconductor investment sentiment fueled by positive cues from the US semiconductor market [13][14][16][18]. Furthermore, news of SK Group Chairman Chey Tae-won's open-market share purchase acted as a major tailwind [13][15][16][18]. The stock also benefited from a broader rally among semiconductor-related equities as the market's "two semiconductor giants" skyrocketed [17].

Sources

1. SK하이닉스 –22.85%, 삼성전자 –17.91%…주가, 이틀 만에 빠졌다 — 한겨레 · 2026-07-29
2. 삼성전자와 SK하이닉스 주가 하락은 "빙산의 일각" 외신 평가, AI 버블 우려 더 커져 — 비즈니스포스트 · 2026-07-30
3. "SK하이닉스 470만원 간다"…주가 빠지자 나온 파격 전망 — 한국경제 · 2026-07-29
4. 주가 폭락 속…한국투자증권 "SK하이닉스 470만원 간다" — 연합뉴스TV · 2026-07-30
5. 최태원, SK하이닉스 주식 48억 규모 장내매수…"책임경영 차원"(종합) — 연합뉴스 · 2026-07-30
6. SK하이닉스 ADR 해외주식 순매수 1위…세금 더 내는데 왜? — 조선일보 · 2026-07-28
7. SK하이닉스 –22.85%, 삼성전자 –17.91%…주가, 이틀 만에 빠졌다 — 한겨레 · 2026-07-29
8. 삼성전자 주가, 오늘 급등한 이유는? — Investing.com 한국어 · 2026-07-30
9. 주가 급락한 삼성전자, 역대급 배당이 방어막 되나 — 경제타임스 · 2026-07-29
10. 삼성전자와 SK하이닉스 주가 하락은 "빙산의 일각" 외신 평가, AI 버블 우려 더 커져 — 비즈니스포스트 · 2026-07-30
11. 삼성전자·하이닉스 프리마켓서 급락…23만·160만원대로 — 문화일보 · 2026-07-27
12. 하이닉스 60조·삼성전자 89조 넘게 벌었는데…주가는 왜? [스프] — v.daum.net · 2026-07-31
13. [ET특징주] 美 반도체 훈풍에 최태원 장내 매수까지… SK스퀘어, 주가 上 — 전자신문 · 2026-07-31
14. 반도체주 투자심리 들썩…삼성전기·SK스퀘어 '상한가' 직행 - 머니투데이 — 머니투데이 · 2026-07-31
15. [특징주] SK스퀘어, 최태원 회장 장내 매수 소식.. '상한가' — 글로벌이코노믹 · 2026-07-31
16. SK하이닉스·SK스퀘어, 美 반도체 훈풍·최태원 매수에 20%대 급등 — 매일신문 · 2026-07-31
17. [특징주] '반도체 투 톱' 폭등에 SK스퀘어 등 관련주도 초강세(종합) — 연합뉴스 · 2026-07-31
18. [특징주] SK스퀘어, 美 반도체 훈풍·최태원 매수에 상한가 직행 — 뉴스핌 · 2026-07-31

This is market commentary, not investment advice.