On July 17, 2x Long MU ETF-Direxion (MUU) fell 9.2% in regular trading, trading at $28.36/share, with turnover of $7.74 billion. The decline was directly triggered by South Korea's Financial Services Commission formally announcing tightened regulations on single-stock leveraged ETFs.

The new regulatory measures include raising the minimum margin requirement from 10 million won to 30 million won (approximately $20,300), accepting only cash as eligible margin, capping single-stock leveraged ETF purchases at 20 shares per transaction, and banning new single-stock leveraged product listings until market conditions stabilize. These measures precisely target the most active speculative capital source in memory stock trading. South Korean retail investors had accumulated approximately 13.67 trillion won in net purchases of 16 single-stock leveraged ETFs since their launch in late May, making this segment a significant liquidity amplifier for the sector.

The policy shock caused SK Hynix to plunge over 11% on the Korean exchange, triggering KOSPI circuit breakers, with the chain reaction rapidly spreading to US-listed memory stocks. The underlying stock Micron Technology fell over 5%, losing its trillion-dollar market capitalization. As a 2x leveraged ETF, the product structure further magnified the underlying asset drawdown.

(The above content is based on publicly available market information, generated by a program or algorithm, and is intended solely as a stock movement alert. It does not constitute investment advice or a basis for trading decisions.)