The closing prices of the Kospi, SK hynix and Samsung Electronics are displayed on a board at Hana Bank's dealing room in Jung-gu, Seoul, on Thursday, when the Kospi reclaimed the 8,000 mark. The index closed up 440.25 points, or 5.76 percent, at 8,088.34, while the Kosdaq rose 1.69 points, or 0.19 percent, to close at 868.41. [Yonhap]
The closing prices of the Kospi, SK hynix and Samsung Electronics are displayed on a board at Hana Bank's dealing room in Jung-gu, Seoul, on Thursday, when the Kospi reclaimed the 8,000 mark. The index closed up 440.25 points, or 5.76 percent, at 8,088.34, while the Kosdaq rose 1.69 points, or 0.19 percent, to close at 868.41. [Yonhap]

The Kospi reclaimed the 8,000 mark last week and has continued its rally, but the market's gains are not spreading evenly. The number of stocks with a market capitalization of at least 1 trillion won ($643 million) — the so-called "trillion-won club," including preferred shares — has actually fallen sharply from two months ago, when the Kospi was trading around the 6,000 level, deepening polarization in the domestic stock market.

According to Korea Exchange, the trillion-won club across domestic markets — the Kospi, Kosdaq and Konex — totaled 314 stocks as of Thursday's closing prices. By market, the breakdown was 235 on the Kospi, 78 on the Kosdaq and one on the Konex.

That marks a steep drop of 91 stocks, or 22.5 percent, in just two months from April 29, when the Kospi closed at 6,690.90 and the trillion-won club surpassed 400 members for the first time in history, reaching 405.

The concentration was evident even at the market's peak. When the Kospi set an all-time closing high of 9,114.55 on June 22, trillion-won club membership on the Kospi stood at just 233 — 34 fewer than at the end of April, even as the index had surged more than 2,400 points in the interim. The figures suggest that the stocks driving the index higher were extremely limited in number.

The top of the domestic market capitalization rankings is dominated by two semiconductor giants. Samsung Electronics and SK hynix led with market caps of 1,809.4 trillion won and 1,728.3 trillion won, respectively.

They were followed by SK Square at 209.7 trillion won, Samsung Electronics preferred shares at 166.9 trillion won, Samsung Electro-Mechanics at 148.6 trillion won, Hyundai Motor at 100.7 trillion won and LG Energy Solution at 84.8 trillion won.

Bonsystems, the sole Konex-listed company in the trillion-won club, had its market cap tallied at 1.04 trillion won. The figure reflects a "kise" — a mechanism that treats the best available asking price as the closing price when no actual trade is executed.

The Kosdaq market bore the brunt of the concentration trend. The number of Kosdaq stocks in the trillion-won club plunged 43 percent, from 137 on April 29 to 78 on Thursday. Kosdaq's share of the overall trillion-won club fell to 24.84 percent — its lowest level in seven months, since Dec. 1, 2025. The Kosdaq index has effectively given back all of its gains this year.

By contrast, the "10 trillion-won club" — stocks with a market cap of at least 10 trillion won — saw a smaller decline.

On April 29, there were 79 such stocks across domestic markets. As of Thursday, that number had slipped to 71, a decrease of eight stocks, or 10.1 percent.

Compared with the trillion-won club's 22.5 percent drop of 91 stocks over roughly the same two-month period, the data show that mid- and small-cap stocks have weakened far more than large caps.

Analysts attribute the divergence to the recent rally being concentrated in a handful of large-cap names.

Large semiconductor stocks such as Samsung Electronics and SK hynix have led the Kospi higher, but the broader base of companies with market caps above 1 trillion won has actually narrowed even as the index climbed. Single-stock leveraged and inverse exchange-traded funds for Samsung Electronics and SK hynix, which launched in late May, may have further amplified the concentration.

"Since the leveraged ETFs were listed, the market-cap weighting of top large-cap stocks has grown even larger, and market volatility is likely to persist," said Lee Jae-won, a researcher at Yuanta Securities Korea.


attom@heraldcorp.com