[Insight & Opinion] The 500 Trillion Won ETF Market Shakes Korea's Foundations: The Stock Exchange Trapped in 'Wag the Dog'

KOSPI Plummets to 6,700 in a Single Day
Ultra-High-Risk Derivatives Amplify Volatility
Comprehensive Overhaul Needed, Including Stress Test Implementation

Last month, global financial media outlets such as The Wall Street Journal published in-depth analyses, unflinchingly targeting the long-standing vulnerabilities of the Korean capital market. According to these foreign press reports and international investment banks, the most critical flaw in Korea’s stock market lies in its ‘distorted volatility,’ which far exceeds the fluctuations warranted by the underlying strength of the economy. As macroeconomic uncertainty has deepened, the KOSPI fell below the 6,000 level on both July 14 and July 16, 2026. In this context, rather than acting as a stabilizing force, the capital market ecosystem is experiencing a vicious cycle in which volatility is maximized by the dominance of certain ultra-high-risk derivative products. Instead of functioning as a buffer when the index declines, speculative capital is artificially amplifying volatility, accelerating the market’s collapse.

The explosive growth of single-stock exchange-traded funds (ETFs) stands at the center of this volatility. Globally, the classical principle of ‘diversification’ in fund management is breaking down. Riding this trend, the asset size of single-stock ETFs—those concentrating investments on a single large-cap stock—has soared by 2.3 times in just one year. In the Korean market as well, the net assets of single-stock and individual leverage ETFs have surpassed 10 trillion won. The problem is that these abnormal products are serving as a trigger—amplifying the ups and downs of stocks like Samsung Electronics and SK hynix by multiple times. Funds flowing through Korea’s entire ETF market, which has now ballooned to around 500 trillion won, are in turn shaking up the underlying spot stock market, causing the classic ‘wag the dog phenomenon’ where the tail wags the dog.

The possibility of convergence with global speculative capital is particularly concerning. Currently, single-stock ETFs listed in Korea are required by the Capital Markets Act to mix a certain proportion of bonds or other instruments with a single stock for stability. However, the U.S. regulatory environment on Wall Street is completely different. In the United States, it is possible to design unlimited leverage and inverse products—2x or 3x—using only single stocks and swap contracts. If ‘SK hynix U.S. Depositary Receipt (ADR)-based single-stock leverage and inverse ETFs’, which represent a key pillar of Korea’s semiconductor sector, are formally launched on the New York market, the impact could be immense. The moment massive short-selling forces and speculative capital from global hedge funds engage, the price of underlying shares in Korea could spiral completely beyond the oversight of Korea’s financial authorities and become playgrounds for the global speculative arena. While the U.S. market may temporarily benefit from rallies, whenever a volatility shock occurs, the entire semiconductor stock ecosystem in Korea could be shaken at its roots—a massive warning signal is now flashing.

In the midst of financial markets becoming a speculative playground, it is necessary to ask what the financial authorities have been doing. The authorities can hardly avoid criticism for neglecting fundamental upgrades to the capital market’s structure or building long-term investment infrastructure, instead indulging solely in boosting trading volumes and quantitative growth while leaving structural risks unchecked. The secret behind the absence of wild roller-coaster swings in developed markets like the United States and Europe lies in the solid presence of long-term institutional investors. In the U.S. market, enormous pension capital flows mechanically and consistently every month into quality blue-chip stocks, serving as a firm buffer that absorbs extreme volatility. In contrast, rather than laying the groundwork to attract long-term capital, the Korean government has instead induced public pension funds to postpone domestic stock portfolio rebalancing to stave off immediate index declines. This policy, intended as a stopgap, has led to a vicious cycle that further burdens the market with long-term distorted volatility. By tolerating the launch of high-risk derivative products aimed at short-term profits, the authorities have contributed to market distortions—an unmistakable policy misstep.

As the KOSPI plummeted, breaking below the 6,800 level during the session, employees were monitoring the stock market, exchange rates, and other factors in the dealing room at the Hana Bank headquarters in Jung-gu, Seoul, on the 16th. On that day, the KOSPI opened at 6,960.50, down 323.91 points (4.45%) from the previous session, while the KOSDAQ index opened at 813.32, down 16.11 points (1.94%). 2026.7.14 Photo by Yongjun Cho

Even now, financial authorities must abandon any short-term, cosmetics-based mindset and undertake comprehensive regulatory reforms aimed at restoring the market’s health. First, strict restrictions must be imposed on excessive leverage in single-stock and thematic ETFs, and regulations on liquidity providers (LPs) should be strengthened. Secondly, to ensure that the 500 trillion won in ETF capital does not destroy the asset markets during major maturity dates or external shocks, it is urgent for regulators to set up a real-time liquidity stress test system linking spot and futures markets. Additionally, bold incentives must be provided for domestic pension funds to make long-term investments in local stocks and for institutional asset allocation to move mechanically and independently, in order to redirect capital trapped in short-term speculative products toward productive, high-quality equities.

Changing only the décor will never prevent a building from collapsing if its very foundation is shaking. Before the tail swallows the dog, it is time to implement real solutions that will safeguard the market’s resilience and integrity.

Professor Wonkyung Cho, Department of Economics, Sejong University

This content was produced with the assistance of AI translation services.