今年夏天，韩国股市经历了剧烈震荡。基准指数Kospi在上半年翻倍后，于七月底急剧下跌。这波涨跌的幕后推手是散户大量购买杠杆型单一股票ETF，这类产品主要追踪三星和SK海力士的表现，利用衍生品放大收益，使散户能获得以往无法取得的杠杆。当市场下挫时，ETF引发的剧烈波动触发了大规模追缴保证金，加深了投资人的损失。

ETF原本是一种低风险的普通指数型工具，旨在让散户以极低成本投资多元化的股票组合。然而，投资公司如今正以更复杂的产品瞄准散户，包括杠杆型单一股票ETF和反向ETF等。这些新型产品将更高风险注入散户投资组合，许多投资人并未完全理解其运作方式。由于每日结算的机制，这类产品在长期持有时可能侵蚀波动较大股票的报酬。今年已有超过一千档ETF上市，其中近四分之一为杠杆型单一股票基金，反映出投机性产品日益泛滥的趋势。（关键数字：1,000）

韩国监管机构已针对国内市场的动荡推出新规定，要求单一标的基金持有人在购买前完成教育课程。文章呼吁其他国家应从韩国的经验中汲取教训，加强资讯揭露要求，提升金融素养教育，并将新型ETF中内建的杠杆纳入审慎监管和压力测试的范畴。高杠杆且散户参与度高的市场，令人不安地联想起历史上的市场崩盘。

South Korea's stock market experienced dramatic turbulence this summer. The Kospi index doubled in the first half of the year before collapsing in late July, driven largely by widespread retail purchases of leveraged single-stock ETFs tracking Samsung and SK Hynix. These products use derivatives to amplify returns, and when the market fell, ETF-driven volatility triggered a wave of margin calls that compounded investor losses.

Originally designed as low-cost, diversified index-tracking instruments, ETFs have evolved into increasingly complex and speculative products. Investment firms now offer leveraged single-stock and inverse ETFs to retail investors, many of whom do not fully understand their mechanics. Due to daily settlement, these products can erode long-term returns on volatile stocks. Over 1,000 new ETFs launched this year alone, with nearly a quarter being leveraged single-stock funds—part of a broader trend that includes cryptocurrencies, prediction markets, and zero-day options resembling gambling more than investing.

South Korean regulators have responded by requiring mandatory education courses for buyers of single-name funds. The article urges other countries to learn from Korea's experience by strengthening disclosure requirements, improving financial literacy, and incorporating the leverage embedded in novel ETFs into prudential stress tests. A highly leveraged market with significant retail participation carries unsettling parallels to past financial crashes.