In this paper, we examine the Federal Reserve’s newest policy tool, known as the overnight reverse repo (ONRRP) facility, to understand its effects on the repo market. Using exogenous variation in the parameters of the ONRRP, we show that private repo activity is crowded out when money funds invest in the ONRRP. Additionally, we find that the ONRRP increases lenders’ bargaining power, thereby raising borrower funding costs. Lastly, we show that repo borrowers reallocate to repo backed by riskier collateral and borrow more from ONRRP-ineligible asset managers, both of which could increase financial vulnerability due to instability in dealer funding. Received April 27, 2017; editorial decision October 19, 2017 by Editor Stijn Van Nieuwerburgh.