Repurchase Agreement
A Repurchase Agreement (repo) is a short-term collateralized borrowing arrangement in which one party sells securities — typically U.S. Treasury securities or agency mortgage-backed securities — to a counterparty with a simultaneous contractual agreement to repurchase the same securities at a specified price on a future date, with the price difference representing the interest cost of the loan.
The repo market is one of the largest and most critical components of the U.S. short-term financing system. At its core, a repo is economically equivalent to a collateralized loan: the seller of the securities receives cash (effectively borrows) and pledges the securities as collateral, while the buyer of the securities provides cash (effectively lends) and holds the collateral as protection against default. The agreement to repurchase at a higher price — the repo rate applied over the term — constitutes the borrower's interest cost.
Repo transactions span a wide range of maturities. Overnight repos are the most common and are repriced daily. Term repos can extend from a few days to several weeks or months. Open repos have no fixed maturity and roll over daily until one party terminates. The Secured Overnight Financing Rate (SOFR), which replaced LIBOR as the primary U.S. dollar overnight benchmark rate, is itself constructed from repo transactions collateralized by U.S. Treasury securities.
Participants in the U.S. repo market include large commercial banks, primary dealers, money market mutual funds, government-sponsored enterprises, hedge funds, and corporate cash managers. Banks and dealers use repos to finance their securities inventories — holding large portfolios of government bonds that are funded day-to-day through the overnight repo market. Money market funds are major cash lenders in the repo market, using high-quality collateralized transactions as a safe and liquid alternative to unsecured bank deposits.
The Federal Reserve uses repo and reverse repo operations to implement monetary policy. The Fed's Overnight Reverse Repo Facility (ON RRP), in which the Fed borrows cash from money market funds and dealers overnight at a policy rate, became a major tool for setting a floor under short-term rates following the expansion of bank reserves after quantitative easing programs. Usage of the ON RRP ballooned to over $2 trillion in 2022-2023 as excess liquidity in the financial system sought a safe overnight return.
Haircuts are a central risk management feature of repo transactions. When the collateral is less liquid or carries greater price volatility than Treasury securities, the lender requires the borrower to deliver securities worth more than the cash lent — the excess representing the haircut. U.S. Treasury collateral typically carries minimal or zero haircuts in standard repo markets, while corporate bonds or agency MBS may carry haircuts of 2% to 10% or more.
The repo market experienced severe stress during the September 2019 repo market disruption, when overnight repo rates spiked to 10% due to a confluence of corporate tax payments, Treasury settlement demands, and reduced bank reserve availability. The Federal Reserve intervened with emergency repo operations to stabilize rates, highlighting the systemic role of this market in U.S. financial plumbing.