On Oct. 8, Samsung Electronics reported a preliminary third-quarter operating profit (an early figure, not yet final) of KRW 107.4 trillion (about $80.2 billion), near a record high. Yet its stock closed down 2.42% that day at KRW 262,000 (about $196). The KOSPI also fell 2.62%. (Dollar figures use the Oct. 8 closing rate of KRW 1,338.5 per dollar.)
Most people assume good earnings lift a stock, and that the big money moving prices comes from foreign investors or pension funds. But the real story is elsewhere. For three weeks starting Aug. 20, the biggest buyer on the KOSPI was "other corporations," and most of that is estimated to be Samsung Electronics and SK hynix buying back their own shares. Samsung has essentially finished its buyback, and SK hynix will finish soon.
- How much has Samsung bought, and how much is left?
A share buyback is when a company buys its own shares on the market. On Aug. 21, Samsung's board approved buying KRW 15 trillion (about $11.2 billion) of its shares, with a plan to buy from Aug. 24 to Nov. 21. By Oct. 6 it had bought about KRW 14.7 trillion (about $11 billion), leaving about KRW 300 billion (about $224 million) as of that date. An Oct. 8 report said its buyback schedule had ended. In share terms, it had already bought 55.8 million shares, more than the 53.29 million it planned.
This KRW 15 trillion is being spent to pay employees in stock. So what held the price up this time was the act of buying itself. When the buying stops, that support stops with it.
SK hynix's board also approved a share purchase worth KRW 40 trillion (about $29.9 billion) on Aug. 19. Of 24.07 million shares, it had bought 18.85 million by Oct. 6. At its recent pace, the remaining 5.22 million or so could be bought within 7 to 8 trading days.
- Who was selling, and who was buying it up?
When a company buys its own shares, Korea Exchange data usually counts it as buying by "other corporations" (ordinary companies, as opposed to individuals, foreign investors and institutions). From Aug. 20, when SK hynix began buying, to Sept. 10, other corporations made net purchases (money spent buying minus money from selling) of KRW 23.384 trillion (about $17.5 billion) on the KOSPI. Over the same period, individuals were net sellers of KRW 17.499 trillion (about $13.1 billion), and foreign investors of KRW 7.946 trillion (about $5.9 billion).
Put simply, other corporations absorbed a large share of the stock that individuals and foreign investors sold. Most of that buying is estimated to be the two companies' buybacks.
Think of a big regular at a flea market who shows up every day and buys up everything. Sellers sell quickly without cutting prices. But this regular came with a fixed budget, and once it's spent, they stop coming.
- What happened on the day the buying slowed?
There was a day that worked like a preview. From Sept. 4 to Oct. 6, other corporations net bought about KRW 1.58 trillion (about $1.18 billion) a day on average, but on Oct. 6 that fell to about KRW 1 trillion (about $750 million). That day, foreign investors net sold about KRW 1.7 trillion (about $1.3 billion), and the KOSPI fell 0.89%.
On Oct. 8, the end of Samsung's buyback schedule was cited as one reason the market fell. Foreign investors net sold about KRW 1.56 trillion (about $1.17 billion) and institutions about KRW 1.16 trillion (about $867 million). Individuals bought about KRW 2.68 trillion (about $2 billion), but the index still fell 2.62%.
If you owned KRW 10 million (about $7,500) of Samsung stock, you lost about KRW 242,000 (about $180) in a single day, the very day record earnings came out (an example based on the 2.42% one-day drop).
- What changes when the buying ends?
No one can say for sure whether the stock will rise or fall. What changes is whose hands set the price. Kang Jin-hyuk, an analyst at Shinhan Securities, called buyers like these other corporations "the fourth source of demand." In other words, a fourth big buyer had joined individuals, foreign investors and institutions. When it leaves, only three remain.
Even in late August, at the height of the buying, the KOSPI stayed in the 6,700-6,900 range. Some said the companies' buying held up the market's floor, while another report said it led the rise. One securities industry official said that once both companies finish buying, "whether foreign investors and institutions are net buyers could have a bigger effect on the index's direction than before."
- BITPRESS Insight
From Sept. 4 to Oct. 6, other corporations net bought about KRW 1.58 trillion (about $1.18 billion) a day on average, and much of that was buybacks of big chip stocks. Once that buyer leaves, even strong earnings only turn into a higher price if someone buys. Oct. 8 can be read as a day that showed that possibility.
So for now, when you look at Samsung's stock price, "do foreign investors and institutions buy on good earnings?" matters more than "are earnings good?" If the stock keeps falling on good news, it means the spot the company used to fill as a buyer is still empty.
Sources
https://biz.heraldcorp.com/article/10895238
https://www.heraldk.com/article/2026091105401437218
https://www.fnnews.com/news/202610061558101841
https://www.businesskorea.co.kr/news/articleView.html?idxno=278527
https://www.mt.co.kr/stock/2026/10/08/2026100815231832416
https://news.mtn.co.kr/news-detail/2026082117561980782
https://www.smarttoday.co.kr/ko-kr/articles/112108
https://sateconomy.co.kr/news/view/1065597228521133
Glossary
Share buyback — A company spending money to buy its own shares on the market.
Other corporations — A category in Korea Exchange trading data that groups ordinary companies, as opposed to individuals, foreign investors and institutions (brokerages, pension funds and so on); most company buybacks are counted here.
Net buying / net selling — Money spent buying minus money from selling: a positive number is net buying, a negative one is net selling.
Preliminary operating profit — Profit from a company's core business announced before its books are closed; the final figure can differ slightly.
Trading day — A day the stock market is open, which excludes weekends and holidays.
KOSPI — South Korea's main stock market index, which tracks the prices of companies listed on the Korea Exchange's main board, such as Samsung Electronics and SK hynix.
BITPRESS articles are information to help your investment decisions, not a recommendation to buy or sell any stock or coin. Investment decisions and their results are your own responsibility.
