Using a unique transaction-level data, we document that only 60% of bilateral repos held by UK banks are backed by high quality collateral. Banks intermediate repo liquidity among different counterparties and use CCPs to reallocate high-quality collaterals among themselves. Furthermore, maturity, collateral rating and asset liquidity have important effects on repo liquidity via haircuts. Counterparty types also matter: non-hedge funds, large borrowers, and borrowers with repeated bilateral relationships receive lower (or zero) haircuts. The evidence supports the adverse selection model of haircuts that we provide, and we do not find significant roles in the data for mechanisms related to lenders’ liquidity position or default probabilities.
