According to Goldman Sachs analysts Timothy Moe and John Kwon, on June 30, a 1 percentage point increase in the combined weight of Samsung and SK Hynix in South Korea's stock index could potentially trigger approximately $2 billion in outflows from the market by foreign investors due to U.S. Investment Company Act diversification requirements.
The bank attributed heightened volatility to structural factors including surging leverage ETF inflows, increased derivatives trading, and margin retail trading activity, which have enabled price swings far exceeding fundamentals-based ranges. Rising valuations have expanded mechanical hedging exposures among institutional investors, raising risks that even moderate market corrections could trigger forced selling cascades.