Rapid growth of money market funds tied to strong equity markets raises systemic risk

A new academic study warns that money‑market funds (MMFs) that expand quickly during periods of strong equity market performance could create systemic vulnerabilities in the global financial system. The research, conducted by economists at the University of Chicago and published in the *Journal of Financial Stability*, analyzes fund flow data from 2005 to 2023 and finds a consistent pattern: inflows into MMFs surge when stock indices rise, leading to larger balances that are increasingly invested in short‑term corporate debt and other higher‑yield instruments. The authors argue that this “flight‑to‑safety” behavior amplifies leverage in the short‑term funding market and raises the likelihood of abrupt withdrawals if equity markets reverse, echoing concerns that surfaced during the 2008 financial crisis.

The study suggests that regulators should enhance monitoring of MMF growth dynamics and consider policy tools—such as liquidity buffers, tiered fee structures, or tighter portfolio composition limits—to mitigate the risk of contagion from rapid fund outflows. By highlighting the link between equity market booms and MMF expansion, the research adds to ongoing debates about the resilience of short‑term funding channels and underscores the need for proactive oversight to preserve financial stability.