KOSPI Closes Up Over 5% on Sharp Gains in Samsung Electronics and SK hynix

Sidecar Triggered in Early Trading; Foreign Investors Buy Over KRW 2 Trillion

Samsung Electronics Up 9%, SK hynix Surges 12% at Close

KOSDAQ Stabilizes in the 840s, Led by Biotech Gains

Market expectations regarding SK hynix’s shareholder return policy were also reflected in Samsung Electronics, with both stocks rising by around 10%. Thanks to the surge in these two leading stocks, the KOSPI index also recorded a gain of over 5%.

On the 20th, as the KOSPI index surged more than 4% in the early session triggering a buy-sidecar, the domestic stock market index was displayed on the electronic board at the Hana Bank dealing room in Jung-gu, Seoul. The USD-KRW exchange rate fell 8.7 won from the previous day's closing price to 1,389 won as of 9:05 AM. August 20, 2026 Photo by Jinhyung Kang

On the 20th, the KOSPI index closed at 6,852.58, up 381.41 points (5.89%) from the previous trading day. By investor type, foreigners were net buyers of KRW 2,270.3 billion, driving the rise in stock prices. Individuals and institutions were net sellers of KRW 2,654.6 billion and KRW 661.8 billion, respectively.

At 9:57:10 a.m. that day, the KOSPI 200 futures index climbed over 5% from the previous session, triggering a buy-side car (suspension of program trading orders) on the Korea Exchange.

By industry, the electrical and electronics sector (+9.19%) posted the most pronounced rise, while manufacturing (+7.10%), securities (+4.46%), retail (+4.16%), and insurance (+3.83%) also climbed by more than 3%. In contrast, some sectors such as transportation and warehousing (-1.08%), finance (-1.12%), and construction (-1.08%) showed weakness.

Among large-cap stocks, SK hynix, which announced its shareholder return policy the previous day, soared by 12.7%, helping SK Square (+11.8%) also close higher. Market leader Samsung Electronics rose 9.4%, just under 10%, while Samsung C&T (+7.7%) and Samsung Life Insurance (+7.6%) also ended higher. Meanwhile, Shinhan Financial Group (-3.7%) and KB Financial Group (-3.8%) performed poorly.

The KOSDAQ index closed at 840.89, up 16.43 points (1.99%) from the previous session. Institutions were net buyers of KRW 106.2 billion, but foreigners and individuals were net sellers of KRW 108.5 billion and KRW 9.2 billion, respectively.

Most sectors on the KOSDAQ closed higher. General services (+5.45%) led the rise, followed by finance (+2.44%), electrical and electronics (+1.89%), pharmaceuticals (+1.85%), and chemicals (+1.53%). Some sectors, such as transportation equipment and parts (-1.08%) and publishing and media reproduction (-0.63%), closed slightly lower or flat.

Among major KOSDAQ stocks, Alteogen (+11.8%), Pharmaresearch (+5.7%), LegoChem Biosciences (+3.7%), ABL Bio (+3.5%), and Samchundang Pharm (+1.7%) posted strong gains. Semiconductor-related stocks such as HPSP (+5.0%), Wonik IPS (+4.2%), and Jusung Engineering (+3.3%) also saw significant increases. On the other hand, HLB (-5.2%) and ISC (-4.8%) declined.

Kyungmin Lee, a researcher at Daishin Securities, analyzed, "A rebound in domestic stocks followed the sharp decline the previous day, as buying on the dip emerged." He added, "Reports that Samsung Electronics is also set to finalize a shareholder return policy this month, following SK hynix, appear to have raised expectations for shareholder returns, which has acted as upward pressure not only on semiconductor stocks but on the domestic stock market overall."

This content was produced with the assistance of AI translation services.