Chip Selloff Pulls KOSPI Down 5.12% as KOSDAQ Rises 2.44%

Samsung Electronics fell 8.76% and SK Hynix 8.79%, dragging the KOSPI down 5.12%. The KOSDAQ moved the other way, rising 2.44% as biotech and robotics shares advanced.

Chip leaders pulled the KOSPI lower

The KOSPI fell 338.00 points from the previous session, while the KOSDAQ gained 17.59 points. Samsung Electronics dropped 8.76% and SK Hynix 8.79%. Because the two companies carry large weights in the KOSPI, their simultaneous declines pulled the index lower.

Unit: KRW trillion

Retail investors bought a net KRW 4.6527 trillion in the KOSPI market, while foreign and institutional investors sold a combined net KRW 4.7737 trillion. The session split retail buying from foreign and institutional selling.

Biotech and robotics lifted the KOSDAQ

Among the KOSDAQ's largest companies by market capitalization, Peptron rose 29.97%, PharmaResearch 9.90%, LigaChem Biosciences 9.03% and ABL Bio 6.29%. ROBOTIS gained 17.25%. While the selloff in large semiconductor stocks was concentrated in the KOSPI, advances in biotech and robotics shares lifted the KOSDAQ.

Foreign investors still sold a net KRW 209.2 billion in the KOSDAQ market. Institutional investors bought a net KRW 166.9 billion, moving in the same direction as the index, but foreign investors were net sellers in both markets.

A lower USD/KRW rate did not bring foreign buying

The USD/KRW reference rate was 1,433.6, down 7.5 from 1,441.1 in the morning briefing. The currency burden highlighted in the morning eased, but foreign investors sold in both the KOSPI and KOSDAQ markets.

The lower exchange rate and foreign buying did not move together in this session. The simultaneous declines in large semiconductor stocks and foreign selling remain relevant alongside next-session flow data.

Next-session checkpoints

• Any stabilization in Samsung Electronics and SK Hynix after their declines
• A reduction in combined foreign and institutional net selling in the KOSPI market
• Follow-through in KOSDAQ institutional buying and strength in biotech and robotics shares

Sources

• Npay Securities KOSPI, 새 창에서 열림 — August 3, 2026 closing index and investor flows
• Npay Securities KOSDAQ, 새 창에서 열림 — August 3, 2026 closing index and investor flows
• Npay Securities KOSDAQ market capitalization, 새 창에서 열림 — August 3, 2026 closing share-price changes
• Npay Securities Samsung Electronics, 새 창에서 열림 — August 3, 2026 close
• Npay Securities SK Hynix, 새 창에서 열림 — August 3, 2026 close
• Npay Securities Peptron, 새 창에서 열림 — August 3, 2026 close
• Bank of Korea ECOS, 새 창에서 열림 — August 3, 2026 USD/KRW reference rate