We construct a simple measure of the aggregate illiquidity of hedge fund portfolios, based on the cross-sectional average first-order autocorrelation coefficient of hedge fund returns, and show that it has strong and robust in- and out-of-sample forecasting power for 72 portfolios of international equities, U.S. corporate bonds, and currencies over the 1994 to 2013 period. The forecasting ability of hedge fund illiquidity for asset returns is in most cases greater than, and provides independent information relative to, well-known predictive variables. We rationalize these findings using a simple equilibrium model, in which hedge funds provide liquidity in asset markets.

Using novel credit data, we show that hedge fund borrowing is significantly overcollateralized, primarily with rehypothecable securities. An idiosyncratic liquidity shock to a major prime broker significantly decreases credit to connected hedge funds. The dominant channel behind this shock transmission is credit supply reduction rather than precautionary demand reduction. Funds posting more rehypothecable collateral are less affected because their collateral alleviates prime broker liquidity constraints. Exposed funds subsequently have lower aggregate credit with worse terms, suggesting imperfect substitutability across hedge fund credit sources. Funds subject to the decrease in balance sheet leverage subsequently increase portfolio illiquidity, embedded leverage, and derivatives exposure.

We estimate the effect of carbon pricing policy on bank credit to greenhouse-gas-emitting firms. Our analyses exploit the geographic restrictions inherent in California’s cap-and-trade bill and a discontinuity in the embedded free permit threshold of the federal Waxman-Markey cap-and-trade bill. Affected high emission firms face shorter loan maturities, lower access to permanent forms of bank financing, higher interest rates, and higher participation of shadow banks in their lending syndicates. These effects are concentrated among private firms, while credit terms of public firms are largely unaffected. Overall, we show that banks respond quickly to realizations of transition risk.

We exploit the 2020 Treasury market shock to analyze how external and internal constraints impact arbitrageurs. Using regulatory filings, we find that hedge funds reduced arbitrage activities and increased cash holdings, despite stable credit and low contemporaneous redemptions. Creditors’ regulatory and liquidity constraints were not propagated to hedge funds through repo—Treasury arbitrageurs’ predominant financing source. Fund-creditor borrowing data reveal more regulated dealers provided, and more important clients received, disproportionately higher funding. Value-at-risk reported by funds suggests internal risk constraints were binding. Our results support theoretical predictions that arbitrageur risk constraints and precautionary liquidity management can amplify market instability even when contemporaneous financing remains resilient.