AI 中文总结
该研究指出2026年韩国市场极端波动源于套利者掠夺杠杆ETF的收盘再平衡，此操作推高年化波动率47个百分点、转移4万亿韩元，改变基准而非分散再平衡可削弱该影响。
AI 中文摘要
我们认为，2026年韩国市场的极端波动是由套利者掠夺杠杆交易所交易基金（LETFs）的收盘再平衡操作所驱动的。LETF必须在收盘时按当日走势方向交易，而收盘同时也是衡量其规模的基准，因此其需求随价格上升，套利者会抢先买入，通过在成交价交易放大订单，随后将其抛售到自己制造的价格波动中。正如预测，在三星电子和SK海力士的产品上市后，其盘前美国新闻相关的价格变动会在一天后反转，对照组则无此现象。在设定的参数下，该循环使年化波动率增加了47个百分点，并在8周内从散户持有者手中转移了4万亿韩元。韩国采取的补救措施是在交易时段内分散再平衡操作，这只是转移了订单但未改变衡量其规模的基准，可能会推高成本；而改变基准则是有效的，平均两次成交价就能将其可制造的影响减半。
英文摘要
We argue that speculators preying on the closing rebalances of leveraged exchange-traded funds (LETFs) contributed to the Korean market's extreme volatility in 2026. An LETF's mandated daily rebalance is sized by the day's return, which generates an upward-sloping demand at market close. In response, rational speculators pre-position, enlarge the fund's order, and liquidate into the demand they have induced. Consistent with this mechanism, Korean stocks tracked by LETFs reverse about 75% of their first-day response to pre-open U.S. news by the next close and oscillate for several days thereafter, a pattern absent in every control group. Our quantification implies that self-reinforcing rebalance raised SK Hynix's annualized volatility from 100.0% to 136.7% over nine weeks and cost its products' predominantly retail holders 17.6% of their initial investment. Dispersing the rebalance across the trading day may backfire, whereas a flexible leverage multiple could help.
