We examine how portfolio regulations affect risk sharing between financial institutions with market power. Unconstrained access to complete markets permits flexible exploitation of market power and induces inefficient risk sharing. Appropriate portfolio restrictions counteract this, improving liquidity and risk sharing by bundling securities with offsetting strategic incentives. However, excessive regulation can be counterproductive, destroying gains from trade. An application of our theory shows that cross-asset...

A key function of financial intermediaries is to borrow in financial markets and lend to firms. I show that this creates informational linkages between repo and corporate bond markets. My key result is improving transparency in either market may lower welfare even if funding liquidity improves. My model’s predictions are consistent with the bond and repo market dysfunction during the 2008 global financial and COVID-19...