Code for: Understanding Collateral Re-use in the US Financial System

We document how primary dealers use and re-use collateral in the United States. Using confidential supervisory data, we map how collateral flows through individual dealers, identifying whether the collateral is encumbered or rehypothecated. From these data we estimate the degree of collateral re-use at the dealer level. We find a high degree of US Treasury re-use, for which we posit three possible drivers: (1) intermediation of cash, (2) intermediation of collateral, and (3) "stripping" and distribution of their safe asset benefits. This work contributes to research aimed at understanding how collateral circulation improves market functioning but may lead to fragility. <br>