South Korea’s KOSPI climbed in early trading on the 8th, reclaiming the 7,000 level. The index opened with gains of around 0.7% from the previous session and rose to 7,047.10 by approximately 9:13 a.m. Even with U.S. markets closed for Labor Day, the launch of OpenAI’s next-generation artificial intelligence model lifted expectations for semiconductor demand, stimulating investor sentiment.

According to the Korea Exchange, as of 9:03 a.m., the KOSPI was trading at 7,025.07, up 29.68 points (0.42%) from the previous session. Supply and demand by investor type showed mixed patterns in early trading. Immediately after the open, retail investors were the sole net buyers, purchasing 57.5 billion won (approximately $42.9 million) to support the index, while foreign and institutional investors sold 60 billion won (approximately $44.7 million) and 4.3 billion won (approximately $3.2 million), respectively. However, ten minutes later, institutional investors flipped to net buying with 206.1 billion won (approximately $153.7 million) in purchases, while retail and foreign investors sold 79.9 billion won (approximately $59.6 million) and 154.9 billion won (approximately $115.5 million), respectively.

This shift in supply-demand dynamics is interpreted as institutional investors stepping in for bargain hunting amid profit-taking following the previous session’s sharp short-term rally. The index opened at 7,045.79, up 50.40 points (0.72%) from the prior session, and extended gains as institutional buying flowed in.

OpenAI’s latest AI model, “GPT-6 Astra,” is seen as boosting expectations for increased computing demand driven by the proliferation of agent-based AI, thereby improving visibility for high-performance memory demand including high-bandwidth memory (HBM) and server DRAM. This has effectively provided breathing room for semiconductor stocks that had been under pressure from supply-demand and sentiment perspectives.

Han Ji-young, an analyst at Kiwoom Securities, said, “South Korea’s stock market is expected to show sector-differentiated trading today, influenced by profit-taking following the previous session’s sharp rally, intraday movements in U.S. 10-year Treasury yields, and news related to the U.S. and Iran.”

Mixed Performance Among Large-Cap Stocks

Large-cap stocks on the KOSPI showed mixed performance. As of 9:13 a.m., Samsung Electronics was up 0.09%, holding modest gains, while SK Hynix rose 0.73%. KB Financial Group (0.80%), SK Square (0.36%), Samsung Life Insurance (0.32%), Samsung C&T (0.26%), and LG Energy Solution (0.14%) also joined the advance. On the other hand, Samsung Electro-Mechanics fell 1.72%, while Hyundai Motor (-0.38%) and Samsung Biologics (-0.07%) also traded lower.

By sector, metals led gains with a 2.11% rise, followed by electrical and electronics (1.37%) and construction (1.36%). Non-metallic minerals fell 0.58%, and food and beverage/tobacco edged down 0.02%.

The KOSDAQ index also rose in tandem. At the same time, the KOSDAQ was trading at 827.36, up 5.17 points (0.63%) from the previous session. In early trading at 9:03 a.m., it had recorded 828.80, up 0.80% (6.61 points). On the KOSDAQ market, foreign and institutional investors sold 39.5 billion won (approximately $29.5 million) and 19.8 billion won (approximately $14.8 million), respectively, while retail investors were the sole net buyers with 58.5 billion won (approximately $43.6 million), supporting the index.

Among top KOSDAQ stocks, Jusung Engineering surged 5.93%, showing notable strength. Simmtech (3.76%), HPSP (3.19%), Wonik IPS (2.98%), EO Technics (2.74%), Leeno Industrial (2.19%), EcoPro (2.06%), and EcoPro BM (1.73%) also rose across the board. Alteogen fell 0.52%.

Korean Won Rebounds… Exchange Rate in 1,340 Won Range

In the Seoul foreign exchange market, the won-dollar exchange rate began daytime trading at 1,341.5 won, down 5.2 won from the previous session (indicating a stronger Korean won). As of 9:00 a.m., it had fallen to 1,340.7 won, moving in the low 1,340 won range.

The rise in South Korea’s stock market on this day is attributed to AI momentum brightening semiconductor demand prospects even amid the absence of U.S. market trading due to the holiday. However, experts note that profit-taking pressure from the sharp short-term rally, along with external variables such as U.S. interest rates and Middle East geopolitical conditions, still remain, and they are watching for the possibility of continued sector rotation trading.