Abstract
Passive capitalization-weighted index funds now surpass active management in aggregate investor allocations. Flows into passive strategies cause unrelated stocks to move synchronously, undermining diversification and potentially increasing systemic risk. New flows into passive products mechanically overweight overvalued stocks and underweight undervalued stocks due to market-price weighting, exacerbating momentum-driven price distortions. Rebalancing at the stock level to non-price-based anchor weights may mitigate these distortions and enhance long-term returns.