[Edaily Reporter kyoungeun kim ] Share buybacks by SamsungElectronics and SK hynix are reshaping the supply-and-demand dynamics of the KOSPI. The traditional trading landscape—divided among retail investors, foreign investors, and institutions—has shifted as “other corporations” have emerged as major buyers, altering the dynamics of “key buying entities.” Given the two companies’ enormous share of the market capitalization and the combined scale of their share buybacks—totaling 55 trillion won—they are gaining enough influence to shake the entire market.
◇“Other Corporations” Behind the “Weak Start, Strong Finish” Trend… Utilization Rate Remains in the 20% Range
On the 1st, on the KOSPI market, SamsungElectronics(005930)opened at 256,500 won, down 1.35%, but narrowed its losses to close 0.38% higher at 261,000 won. SK hynix(000660)also fell as low as 1,652,000 won early in the session but rebounded to close 1.14% higher at 1,693,000 won.
Risk-averse sentiment weighed on the market early on—driven by the resumption of military clashes between the U.S. and Iran, declines in New York’s three major indices, and the sharp rise in international oil prices and long-term interest rates—causing the index to open lower. However, the KOSPI ultimately closed up 0.23% at 6,835.80 points toward the end of the session.
The previous day, the KOSPI also plunged more than 3% early in the session amid concerns over further U.S. monetary tightening, caution regarding the growth of China’s Changxin Memory (CXMT), and geopolitical tensions in the Middle East, but it recovered its losses to close up 0.46% at 6,820.02.
Behind the “weak start, strong finish” trend among major semiconductor stocks was buying pressure from “other corporations.” These entities made net purchases totaling 1.6657 trillion won on the day. The three major investor groups—retail investors (539.8 billion won), foreign investors (486.7 billion won), and institutional investors (633.9 billion won)—all recorded net sales. The structure of the market saw “other corporations” absorb the entire net selling volume from these three groups. For the second consecutive day, “other corporations” have been the sole force driving the market.
Other corporations have continued to make net purchases for nine consecutive trading days since SK hynix decided to buy back its own shares on the 20th of last month. Their net purchases have consistently exceeded 1 trillion won since that date.
When a listed company buys back its own shares on the open market, these transactions are classified as “other corporations”—meaning general corporations rather than financial institutions—in the exchange’s investor-specific supply-and-demand data.
SamsungElectronics and SK hynix are at the center of this buying spree. SK hynix has decided to acquire 24.07 million shares of its own stock, valued at 40 trillion won, and cancel them in their entirety, while SamsungElectronics has decided to purchase approximately 53.29 million common shares, valued at 15 trillion won, for employee compensation.
Based on the cumulative executed volume reported in their treasury stock acquisition filings, SamsungElectronics has purchased 3.5445 trillion won worth of shares, while SK hynix has purchased 8.7820 trillion won worth. The combined total for the two companies is 11.8365 trillion won, leaving them with purchasing capacity for approximately 43 trillion won worth of shares going forward.
◇ From “Other” to “Core” Entities
This supply-and-demand dynamic is assessed as differing in nature from past cases. Over the past decade, there were six instances between 2016 and 2017 when individual investors, foreign investors, and institutional investors were all net sellers, while only “other corporations” were net buyers. However, at that time, the net purchases by other corporations were at typical levels ranging from 51.2 billion to 104.3 billion won per day, and this pattern arose because the trading volumes of other entities were negligible.
In contrast, this time, after SamsungElectronics and SK hynix announced plans to repurchase a total of 55 trillion won worth of their own shares in advance and began actual on-market purchases, net buying by “other corporations” has continued for nine consecutive trading days. The most significant difference is that substantial, genuine demand—which can be gauged by the buyers, scale, and duration—has materialized.
While “other corporations” previously served as a supplementary source of demand that helped limit index declines, they are now viewed as a key source of demand that directly influences the stock prices of the two largest companies by market capitalization and the direction of the KOSPI. Some observers suggest that if top-market-cap companies proceed with large-scale share buybacks and cancellations, “other corporations” could establish themselves as the fourth key buyer in the KOSPI market, following retail investors, foreign investors, and institutions.
The securities industry believes that, as the Corporate Value-Up Program has increased the likelihood that listed companies will utilize share buybacks and cancellations—alongside expanded dividends—as key means of enhancing corporate value, the influence of “other corporations” on stock market supply and demand could gradually expand. The number of listed companies that have announced corporate value enhancement plans has surged from 92 at the end of 2024—when the program was introduced—to 169 at the end of 2025, and to 747 as of the end of July this year. The market capitalization of these companies accounts for 84.6% of the total stock market.
Kwon Beom-seok, a senior researcher at SamsungSecurities, said, “If these two companies continue their share buybacks at the current pace, the trend of net buying by other corporations is expected to continue for about 30 trading days, or at least a month and a half.”
However, share buybacks do not guarantee an index rise. Kang Jin-hyuk, an analyst at Shinhan Investment Securities, pointed out, “Since share buybacks are not an upward driver, a shift toward foreign buying is necessary, driven by confirmation of favorable business conditions and the easing of macroeconomic uncertainties.”