A bank repurchase agreement, usually called a repo, is a short-term deal in which one party sells a security and at the same time agrees to buy it back on a set future date at a slightly higher price. The gap between the two prices is effectively interest, which makes the arrangement function economically like a very short-term loan backed by collateral. The U.S. repo market averaged roughly $12.6 trillion in daily exposures as of the third quarter of 2025, making it the single largest source of short-term funding in the financial system.1Office of Financial Research. Sizing the U.S. Repo Market
How the Two Legs Work
A repo has two legs. On the first, the party that needs cash (the “seller”) transfers a security to the party providing cash (the “buyer”) and receives the agreed purchase price by wire. On the second, the seller buys the same security back at a predetermined higher price. That price difference is the buyer’s interest for parking its cash.
A simple example: a bank sells $10 million in Treasury notes to a money market fund and agrees to buy them back the next morning for $10,001,389. The $1,389 difference is the interest payment. Annualized, that implied rate is the repo rate, which represents the seller’s borrowing cost and the buyer’s return on a secured, short-term investment.
Legally the deal is structured as a sale and repurchase, not a loan. The buyer takes actual legal title to the security for the life of the transaction. Economically, though, it works like a collateralized loan, and that dual nature matters: the sale form gives the buyer legal protections in bankruptcy that an ordinary lender wouldn’t have, while the accounting treats the transaction as a secured borrowing.
Haircuts, Margin Calls, and Collateral Management
The buyer doesn’t hand over cash equal to the full market value of the collateral. A protective discount called a haircut is applied. If a security is worth $100 million and the haircut is 2%, the buyer lends only $98 million. That $2 million buffer protects the buyer if the seller defaults and the security has lost value by the time the buyer can sell it.
Haircut sizes depend on what secures the deal. According to the Office of Financial Research, over 60% of Treasury-collateralized repos carry a zero haircut, reflecting how liquid those securities are. For non-Treasury collateral the picture flips: roughly 69% of those repos carry haircuts above 2%.2Office of Financial Research. Are Zero-Haircut Repos as Common as Advertised Corporate bonds, asset-backed securities, and less liquid collateral generally require 5% or more.
For repos lasting longer than one day, the collateral is revalued each business day through mark-to-market. If the security’s price drops and the haircut cushion thins below the agreed threshold, the seller must post additional collateral or return some cash. That demand is a margin call. The reverse applies too: if collateral appreciates, the buyer returns the excess. These daily adjustments keep the protective margin roughly constant through the life of the deal.
Common Types of Repos
Overnight and Term
Most repos are overnight, executed one afternoon and unwound the next business morning. Banks and dealers use them to square cash positions at day’s end. Term repos run for a set period beyond one day, sometimes weeks or months. Because the cash is locked up longer, term repos carry more interest rate risk and demand tighter collateral management, but they give a dealer stable financing for a specific position instead of rolling overnight funding every morning.
Bilateral and Tri-Party
In a bilateral repo, the seller and buyer deal directly, and the buyer takes custody of the collateral. In a tri-party repo, a third-party custodian (typically a large clearing bank) sits between them, holding the collateral, handling settlement, calculating haircuts, and managing daily revaluation.3Office of Financial Research. Repo FAQ The tri-party structure also allows collateral substitution during the life of the deal. That operational support makes tri-party the default for high-volume general-collateral trades.
What Collateral Backs a Repo
Not every security qualifies. The commonly accepted categories include:
- U.S. Treasury bills, bonds, and notes, often at zero or near-zero haircuts.
- Treasury Inflation-Protected Securities (TIPS), on similar terms to other Treasuries.
- Agency mortgage-backed securities from Fannie Mae, Ginnie Mae, and Freddie Mac.
- Government-sponsored enterprise debt from the Federal Home Loan Banks, Federal Farm Credit Banks, and similar agencies.
- STRIPS, where Treasury or agency coupons have been separated from principal.
These categories reflect what FICC’s GCF Repo service accepts for general-collateral trading.4DTCC. GCF Repo Service Bilateral repos can accept a wider range by private agreement, including investment-grade corporate bonds and some asset-backed securities, but with larger haircuts to compensate for lower liquidity.
Who Uses Repos and Why
For sellers, the repo market is cheap, reliable short-term funding. A bank holding $500 million in Treasuries can convert part of that portfolio to overnight cash to meet reserve targets or fund lending, without selling the bonds. Broker-dealers do the same to finance trading inventories. Because the borrowing is secured, the rate is typically lower than unsecured interbank lending.
For buyers, repos are a low-risk way to earn a return on idle cash. Money market funds are among the largest buyers. A fund sitting on $2 billion can lend it overnight against Treasury collateral with minimal credit risk; if the borrower defaults, the fund already holds the Treasuries and can sell them. Corporations with large treasury operations use repos the same way.
Standardized documentation keeps transaction costs low. SIFMA’s Master Repurchase Agreement provides a pre-printed framework covering default remedies, margin maintenance, and netting rights, so counterparties don’t negotiate a new contract for each trade.5SIFMA. MRA and GMRA Documentation
How Repo Rates Feed Into SOFR
The repo rate on a given trade reflects supply and demand for cash versus collateral that day, counterparty credit, collateral quality, and term. In aggregate, repo rates tend to trade near or within the Federal Reserve’s target range for the federal funds rate, because the Fed uses repo-based tools to anchor short-term rates.
The most important benchmark that comes out of the repo market is the Secured Overnight Financing Rate (SOFR). Published each business day by the Federal Reserve Bank of New York, SOFR is a volume-weighted median of actual overnight Treasury repo transactions, drawing on tri-party data, GCF Repo data, and bilateral Treasury repos cleared through FICC’s delivery-versus-payment service.6Federal Reserve Bank of New York. Secured Overnight Financing Rate Data SOFR replaced LIBOR as the primary reference rate for trillions of dollars in floating-rate loans, derivatives, and other contracts. When a mortgage or corporate loan is tied to SOFR, the rate the borrower pays is driven by conditions in the repo market.
The Federal Reserve’s Role
The Fed participates directly in the repo market to steer short-term rates. Two standing facilities anchor the system.
The overnight reverse repo (ON RRP) facility lets eligible institutions like money market funds deposit cash with the Fed overnight in exchange for Treasury collateral. The ON RRP rate, currently 3.50%, functions as a floor under short-term rates.7Federal Reserve Bank of New York. Reverse Repo Operations No rational cash provider would lend privately below what the Fed offers risk-free.
On the other side, the Standing Repo Facility (SRF), operational since 2021, provides a ceiling. Eligible counterparties can borrow overnight from the Fed against Treasury and agency collateral at the SRF rate, which limits upward pressure on overnight rates when private cash is scarce.8Federal Reserve Board. Standing Repurchase Agreement Operations The two facilities create a corridor that keeps the federal funds rate inside the FOMC’s target range. The ON RRP operates on a one-day cycle.9Federal Reserve Board. Overnight Reverse Repurchase Agreement Operations
The Main Risks
Counterparty and Collateral Risk
The most direct risk is that the seller defaults and never repurchases the security. The buyer’s first defense is the collateral itself, with the haircut adding cushion. But if markets are falling fast and the collateral has lost more value than the haircut covers, the buyer takes a loss even though the deal was “secured.” A $100 million security with a 2% haircut that drops to $95 million leaves the buyer $3 million short of the $98 million it lent. This collateral risk is sharpest during broad market stress, when many securities lose value at once.
Liquidity Risk and Repo Runs
Because most repo funding is overnight, borrowers must roll positions every morning. If cash providers collectively refuse to renew, a dealer can lose its entire funding base in a single day. That is a repo run, and it played out in September 2019.
On September 17, 2019, corporate tax payments and Treasury settlement drained cash from the system faster than the market could absorb. SOFR spiked above 5%, and the effective federal funds rate jumped to the top of its target range. The Fed responded within hours, conducting an overnight repo operation that injected $53 billion, with additional operations totaling $75 billion offered each morning for the rest of the week.10Federal Reserve Board. What Happened in Money Markets in September 2019 The episode is a big part of why the Fed later made the Standing Repo Facility a permanent backstop.
Systemic Concentration
The size of the repo market means disruptions don’t stay contained. When a major dealer can’t fund itself, it’s forced to sell securities quickly. Fire sales push prices down, which impairs collateral backing other dealers’ repos, which triggers more margin calls and more forced selling. That feedback loop is what regulators worry about, and it motivates the push toward central clearing.
Why Repos Get Special Bankruptcy Treatment
One of the most important legal features of repos is their treatment in bankruptcy. Under ordinary bankruptcy rules, an automatic stay freezes creditors’ ability to collect against a debtor’s assets. Repos are carved out.
Section 559 of the Bankruptcy Code states that a repo participant’s right to liquidate, terminate, or accelerate a repurchase agreement cannot be stayed, avoided, or limited by the bankruptcy court.11Office of the Law Revision Counsel. United States Code Title 11 – Section 559 If a repo seller files for bankruptcy, the buyer can immediately liquidate the collateral without waiting for court approval. Section 362(b)(7) reinforces this by exempting repo setoff and netting rights from the automatic stay.12Office of the Law Revision Counsel. United States Code Title 11 – Section 362
These safe harbors exist because the market depends on them. If buyers had to wait months or years for a court to release collateral, no rational lender would provide overnight cash. The protections keep repos functioning as near-cash instruments. The Bankruptcy Code defines qualifying repos broadly, covering Treasuries, agency securities, mortgage-related securities, certificates of deposit, and certain foreign government obligations, with a maximum term of one year.13Office of the Law Revision Counsel. United States Code Title 11 – Section 101
The 2026 and 2027 Central Clearing Mandate
Historically, most repos cleared bilaterally or through tri-party arrangements without a central counterparty guaranteeing both sides. That’s changing. In December 2023, the SEC adopted amendments to Rule 17ad-22 requiring covered clearing agencies to mandate that their direct participants submit all eligible secondary-market Treasury transactions for central clearing.14U.S. Securities and Exchange Commission. SEC Extends Compliance Dates and Provides Temporary Exemption for Rule Related to Clearing of U.S. Treasury Securities
The compliance timeline was extended by one year from the original dates. Eligible Treasury cash transactions must be centrally cleared by December 31, 2026, and eligible repo transactions by June 30, 2027.15U.S. Securities and Exchange Commission. Treasury Clearing Implementation In practice, FICC’s Government Securities Division will become the central counterparty for a much larger share of the market, stepping between buyer and seller and guaranteeing both legs. That reduces the bilateral counterparty risk that can amplify stress events like 2019. Clearing costs may rise for firms that previously avoided central clearing, but regulators view a centrally cleared market as easier to monitor, more efficient at netting exposures, and less prone to cascading failures.
Accounting Treatment
Despite their legal form as sales, most repos are recorded as secured borrowings. Under FASB ASC Topic 860, a repo is accounted for as a financing arrangement when three conditions are met: the securities to be repurchased are the same or substantially the same as those transferred, the repurchase price is fixed or determinable, and the repurchase agreement was entered into at the same time as the original transfer.16Financial Accounting Standards Board. Transfers and Servicing (Topic 860) Reconsideration of Effective Control for Repurchase Agreements Nearly every standard repo meets all three.
Under secured-borrowing treatment, the seller keeps the securities on its balance sheet and records a liability for the cash received. The buyer records a receivable rather than an investment in the securities. The difference between the sale price and repurchase price is recognized as interest expense for the seller or interest income for the buyer over the life of the agreement. That treatment matches the economic reality both parties understand from the start: the securities are coming back, and the cash transfer is temporary.