SK Hynix's single-day decline exceeds 12%, and the Hong Kong stock ETF that is twice leveraged on Hynix's shares has a scale approaching $17 billion, which is already capable of influencing the market rather than simply following the underlying asset.

This ETF is designed to aim for "double volatility" of Hynix's stock price every day, requiring frequent rebalancing of positions: when the underlying rises, it passively buys more; when it falls, it passively sells.
Someone has estimated that if Hynix's volatility that day is 5%, the ETF rebalancing could involve about $1.7 billion in funds.
Compared to Hynix's previous trading day with an approximate trading volume of $11.2 billion, such rebalancing is equivalent to nearly 15% of intraday trading being driven by mechanisms, which can amplify gains and losses during sharp fluctuations, creating a cycle of "price → passive trading → greater price volatility."
Korean regulators have stated that they are considering taking separate measures against such leveraged ETFs; if rules are tightened in the future, it could both ease volatility and cause short-term shocks to the liquidity of related products and underlying stocks.