The KOSPI slid more than 1% intraday before reversing higher in late trading to close in the 6,830 range. While retail investors, foreign investors, and institutions all turned net sellers, Other Corporations—which reflects Samsung Electronics and SK Hynix share buybacks—defended the index with net purchases exceeding ₩1.6 trillion (approximately $1.2 billion). In contrast, the KOSDAQ fell more than 1.5% amid combined selling by foreign and institutional investors, declining for a second consecutive session.
On September 1, the KOSPI closed at 6,835.80, up 15.78 points (0.23%) from the previous session. The index opened at 6,784.29, down 35.73 points (0.52%) from the prior close, then slid as low as 6,732.47, marking a 1.28% decline. It subsequently pared losses and fluctuated before turning higher in late trading. This marked a second straight session of “weak start, strong finish,” following the previous day’s pattern of an early drop of more than 3% before a rebound.
On the main KOSPI board, retail investors, foreign investors, and institutions were all net sellers. Retail investors sold a net ₩539.7 billion (approximately $392.9 million), foreign investors sold a net ₩486.7 billion (approximately $354.4 million), and institutions sold a net ₩634 billion (approximately $461.6 million). Meanwhile, Other Corporations were the sole buyers, purchasing a net ₩1.6657 trillion (approximately $1.2 billion) to support the index’s downside. Other Corporations extended their net buying streak to 10 consecutive sessions, driven by Samsung Electronics’ employee stock compensation-related buybacks and SK Hynix’s share repurchases for cancellation.
Since SK Hynix began its buyback program on August 20, net purchases by Other Corporations have exceeded ₩1 trillion (approximately $728.1 million) daily. After Samsung Electronics joined the buying on August 24, daily net purchases have ranged between ₩1.5 trillion and ₩1.6 trillion. The steady accumulation of net buying—ranging from a minimum of ₩200 billion (approximately $145.6 million) to nearly ₩300 billion (approximately $218.4 million) per time block—is seen as having defended the index throughout the session.
Large-cap stocks were mixed. Samsung Electronics closed at ₩261,000 (approximately $190), up ₩1,000 (0.38%) from the previous session, while SK Hynix rose ₩19,000 (1.14%) to ₩1.693 million (approximately $1,200). SK Square gained 2.89%, Samsung C&T rose 3.72%, and SK Innovation jumped 7.81%. On the downside, Samsung Electro-Mechanics fell 1.92%, LG Energy Solution dropped 2.91%, and Hyundai Motor declined 0.74%. Hanwha Aerospace slid 3.99%.
Foreign investors showed divergent trading in the top-cap names Samsung Electronics and SK Hynix. They sold a net ₩184.5 billion (approximately $134.3 million) worth of Samsung Electronics common shares while buying a net ₩166.8 billion (approximately $121.4 million) worth of SK Hynix—their largest purchase. They also bought a net ₩20.4 billion (approximately $14.9 million) worth of Samsung Electronics preferred shares. Samsung Electronics preferred shares are drawing attention on expectations that their weighting could increase in future buyback and cancellation programs. Non-voting preferred shares are interpreted as being excluded from equity holding limits under South Korea’s Financial Holding Companies Act, meaning they can avoid the additional stake sale burden on financial affiliates that common shares would face.
By sector, retail rose 2.98%, insurance gained 2.15%, financials added 1.52%, electricity and gas climbed 0.92%, and telecommunications advanced 0.85%. On the downside, construction fell 3.50%, machinery and equipment dropped 1.34%, food, beverage and tobacco declined 1.24%, and transportation equipment and parts lost 1.19%.
The KOSDAQ closed at 821.25, down 13.04 points (1.56%) from the previous session, marking a second consecutive decline. Intraday, the index slid as low as 815.52, representing a 2.25% drop. On the KOSDAQ market, foreign investors and institutions sold a net ₩226.7 billion (approximately $165.1 million) and ₩286.3 billion (approximately $208.4 million), respectively, while retail investors bought a net ₩518.1 billion (approximately $377.2 million).
Among KOSDAQ large caps, Alteogen fell 2.11%, EcoPro dropped 4.49%, and EcoPro BM declined 3.81%. Rainbow Robotics slid 2.39% and Wonik IPS lost 1.35%. HPSP and Voronoi rose 1.59% and 0.61%, respectively.
In Seoul’s foreign exchange market, the won-dollar exchange rate stood at ₩1,370.4 (approximately $1) as of 3:30 p.m., up ₩1.8 from the previous session.
Lee Kyung-min, an analyst at Daishin Securities, said, “In the South Korean stock market, expanded net buying by Other Corporations drove the index higher. However, with external uncertainties persisting, overall market sentiment weakened and the index’s upside was limited.” External uncertainties, including U.S. and Middle East conflicts, appear to have capped the upside.