The benchmark KOSPI closed at 6,813.34, up 234.30 points or 3.56 percent from the previous session. The index climbed as high as 6,895.63 during the day before paring some gains, but recovered to close above 6,800 for the first time in about three weeks.
The rally spread beyond the country's two biggest chipmakers, though most of the gains still came from tech stocks and companies linked to the semiconductor supply chain.
Electronic equipment and devices led KOSPI with a 9.28 percent gain, while semiconductors and semiconductor equipment rose 5.15 percent. Venture investment firms gained 5.91 percent, followed by aerospace and defense at 3.30 percent and wireless communications services at 2.55 percent.
Among major technology stocks, Samsung Electronics closed 4.89 percent higher at 268,000 won, while SK hynix gained 5.92 percent to 1,593,000 won. SK Square jumped 9.08 percent to 1,117,000 won.
Electronic components maker Samsung Electro-Mechanics surged 12.58 percent to 1,503,000 won after global investment bank Morgan Stanley named it its top pick among Korean technology stocks, citing growing demand and tighter supplies of multilayer ceramic capacitors or MLCCs, tiny components that help regulate power in AI servers.
The gains across chipmakers, equipment producers and component suppliers showed the rally extending further into the semiconductor and AI hardware supply chain. But the buying remained largely driven by foreign and institutional investors rather than retail investors.
Foreign investors bought a net 2.11 trillion won (US$1.49 billion) of KOSPI shares, while institutions added 681.7 billion won. Retail investors sold a net 2.74 trillion won, taking the other side of Thursday's rally.
The return of foreign buying came amid improving global market sentiment. AI infrastructure stocks rallied sharply in the U.S. the previous day, with CoreWeave surging 19.28 percent and Super Micro Computer jumping 19.02 percent amid continued optimism over demand for AI computing infrastructure. Micron Technology gained 4.92 percent, helping lift the Philadelphia Semiconductor Index 2.49 percent.
U.S. inflation data also helped support risk sentiment. Consumer prices rose 3.4 percent in July from a year earlier, slowing from 3.5 percent in June, while core inflation eased to 2.5 percent from 2.6 percent.
The rally was much weaker on the KOSDAQ, where investor flows told a different story. The junior index closed just 0.29 percent higher at 861.37 after swinging between 853.09 and 870.96 during the session.
Retail investors led the buying, purchasing a net 257.1 billion won, while foreign and institutional investors sold 136.3 billion won and 115.8 billion won, respectively. The modest gain came as the KOSDAQ faced tighter regulations, with dozens of companies placed under watch for failing to meet stricter minimum market capitalization requirements.
But the tepid gain did little to dampen semiconductor-related stocks, which remained among the stronger performers. Chip equipment maker Jusung Engineering climbed 3.05 percent to 179,300 won, while Wonik IPS jumped 7.62 percent to 120,000 won. Robot maker Rainbow Robotics gained 1.43 percent to 497,000 won.
The Korean won weakened slightly despite the stock rally, trading at 1,423.50 won against the U.S. dollar, compared with 1,415.70 won in the previous session.
Other major Asian markets also made similar moves, with Japan's Nikkei 225 rising 1.16 percent to 68,308.59, supported by chip stocks and a stronger corporate earnings outlook as softer U.S. inflation reduced expectations of a Federal Reserve rate hike in September.
China's Shanghai Composite fell 0.50 percent to 3,926.96, while Hong Kong's Hang Seng Index slipped 0.25 percent to 25,377.03.
AJP Takeaways:
- South Korea's benchmark KOSPI closed 3.56 percent higher at 6,813.34 on Aug. 13, 2026, reclaiming the 6,800 level as foreign investors returned to the market.
- Foreign investors bought a net 2.11 trillion won ($1.49 billion) of KOSPI shares, while institutional investors purchased 681.7 billion won and retail investors sold 2.74 trillion won.
- The rally spread beyond Samsung Electronics and SK hynix into the broader semiconductor and AI hardware supply chain, with Samsung Electronics rising 4.89 percent, SK hynix 5.92 percent and Samsung Electro-Mechanics 12.58 percent.
- Samsung Electro-Mechanics surged after global investment bank Morgan Stanley named it its top pick among Korean technology stocks, citing growing demand and tighter supplies of multilayer ceramic capacitors used in AI servers.
- South Korea's KOSDAQ gained a more modest 0.29 percent to 861.37 on Aug. 13, 2026, with retail investors buying a net 257.1 billion won as foreign and institutional investors remained net sellers.
- South Korean technology shares were supported by gains in U.S. AI infrastructure stocks and softer U.S. inflation data, with July 2026 consumer prices rising 3.4 percent year on year, down from 3.5 percent in June.
Copyright ⓒ Aju Press All rights reserved.
