Hedge funds now hold about $13 trillion in gross assets—roughly triple 2013—and around $40 trillion of gross notional exposure, according to the IMF. They also held about 9% of U.S. Treasuries in 2025. The sharper finding is at the position level: in the IMF sample, the most crowded stocks were roughly 10 percentage points more volatile than the least crowded and suffered drawdowns about 4 points deeper. IMF analysis
Crowding is therefore not merely a popular-name problem. Leverage, shared financing and synchronized redemptions can turn apparent liquidity providers into forced sellers at the same moment. The question for a risk review is: how much of the book's liquidity assumes that everyone else's financing remains intact?