KOSPI Plunges 8%: Fifth Trading Halt in a Month and $360 Billion Evaporated — My Analysis of Five Structural Causes
South Korea's stock market is experiencing an unprecedented crisis. The KOSPI index fell more than 8% again today, marking the fifth forced trading halt in the past month. Over 400 trillion won ($360 billion) has "evaporated" from the market. Shares of giants Samsung and SK Hynix each plunged by about 9%.
This decline is not a coincidence but a natural outcome of accumulated structural imbalances. I highlight five key factors that have turned the KOSPI into a "powder keg."
Five Reasons for Extreme Volatility
The first factor is the retail structure of the market. Unlike developed markets dominated by institutional investors, the majority of traders in Korea are so-called "ants." These retail investors operate on a principle of quick entry and even quicker exit. Any dip instantly turns into a panic-driven crash, and any rebound into a sharp spike. This creates a "domino effect" where panic breeds more panic.
The second factor is monstrous concentration. Samsung and SK Hynix together account for 45–50% of the entire KOSPI index. For comparison, Nvidia and Apple make up only 14% of the S&P 500. Essentially, two stocks control the fate of an entire country's market. A drop in one of them sends the index plummeting.
The third factor is record margin debt. It has reached 32.67 trillion won ($22.4 billion), increasing by 25% year-over-year. Leveraged ETFs on individual Samsung and SK Hynix stocks, approved in May, double daily movements. A 9% drop turns into an 18% loss for holders, triggering a cascade of forced sell-offs. This is a self-destruct mechanism.
The fourth factor is the status of the won (KRW). The Korean currency is considered "local" and is not part of global reserves. Therefore, selling by foreign investors hits it harder. The won has already fallen to a 17-year low, raising import costs and limiting the Bank of Korea's ability to cut rates even amid the stock crash. The central bank's hands are tied.
The fifth factor is the National Pension Service of Korea (NPS). This fund holds assets equal to 60% of the country's GDP, but it has already exceeded its limit on the share of stocks in its portfolio. As a result, it is forced to sell on every rebound instead of buying the dips. The NPS was even selling on the day the trading halt was triggered. A fund that should be a stabilizer has itself become a source of pressure.
Loss of a Stabilizer and Bullish Scenario
An additional blow came at the end of June when Korea was not included in the MSCI watch list for an upgrade to developed market status. This deprived the market of the only catalyst for which foreign capital was willing to tolerate volatility. Now, investors have no reason to hold Korean assets.
In the end, the market turned out to be retail-driven, concentrated on two stocks, overloaded with leverage, vulnerable in terms of currency, devoid of stabilizers, and without a bullish scenario. That is why the index no longer moves by 2%—it fluctuates by 8–10% almost every day. Between crashes, the market rebounds just as sharply: in March, it surged nearly 10% in a single day right after a record 12% drop.
My conclusion: The KOSPI is trapped by its own structure. Until the balance between retail and institutional players shifts, until the concentration on two issuers decreases, and until the margin debt problem is resolved, we will see these "roller coasters" again and again. The current situation is not a crisis but the new normal for the Korean market.