Recent discussions highlight the impact of passive investing on market dynamics, with a notable $5 trillion shift from high-cost active management to low-cost passive strategies over the past decade. A new academic paper suggests that the rise of index funds has led to increased market volatility, as active investors are not trading aggressively enough to counterbalance this growth. Critics argue that the efficient-market theory is being challenged in this environment, where passive strategies dominate. The paper indicates that this shift may be contributing to fragile market movements.