Open Repurchase Agreement: Daily Rollover, Collateral, and Risks

An open repurchase agreement is a short-term secured financing arrangement in which one party sells securities to another for cash and agrees to buy them back later, with no fixed maturity date. The deal rolls forward automatically each business day and continues until either side gives notice to end it. That open-ended structure is what sets it apart from a term repo, which locks both sides in for a set number of days.¹

How the Daily Rollover Works

Every repurchase agreement has the same core shape. The borrower sells securities to the lender for cash and commits to repurchase them at a slightly higher price. That price difference is the interest on the loan. The securities sit with the lender as collateral, which is what makes the transaction a secured loan rather than a genuine sale.

In an open repo, no one sets a repurchase date. Each business day, the agreement simply renews. Neither party has to negotiate a new contract or process a fresh settlement. Think of it as a chain of overnight loans stitched together into one continuing transaction: the cash stays with the borrower, the securities stay with the lender, and the trade ticks forward until someone calls it.¹ Either side can terminate on any business day by giving notice within an agreed window.

How Interest Is Set and Paid

The rate on an open repo can be fixed at the outset and left in place until the parties agree to reset it, or it can float against a benchmark that updates automatically. Floating against a benchmark is the more common approach today. For U.S. dollar repos, that benchmark is usually the Secured Overnight Financing Rate (SOFR), a broad measure of the cost of borrowing cash overnight against Treasury collateral.²

The New York Fed publishes SOFR each business day around 8:00 a.m. ET. It is calculated as a volume-weighted median of three underlying data sources: tri-party repo data from the Bank of New York Mellon, general collateral financing repo data, and bilateral Treasury repo transactions cleared through the Fixed Income Clearing Corporation.² Because SOFR is built from real overnight repo activity, an open repo referenced to it moves in step with the wider market.

Interest accrues daily and is not compounded. For open repos held over longer stretches, the accumulated interest is typically settled once a month in a lump sum rather than paid out day by day.¹ The day count convention is Actual/360, standard for U.S. money market instruments: the daily rate equals the annualized rate times the actual number of days, divided by 360.³

Collateral, Haircuts, and Margin Calls

Collateral is what turns a repo from an unsecured loan into a secured one. U.S. Treasury securities dominate the collateral pool, with agency debt, agency mortgage-backed securities, and investment-grade corporate bonds filling in the rest.

A haircut is the discount applied to the collateral’s market value relative to the cash it secures. A 2% haircut means the borrower pledges $102,000 of securities to receive $100,000 in cash. That cushion protects the lender if the collateral’s price falls. Haircut sizes track collateral quality closely. More than 60% of Treasury-backed repos carry a zero haircut, reflecting the near-zero credit risk of U.S. government debt. For non-Treasury collateral, the picture flips: roughly 69% of those trades carry haircuts above 2%.⁴

Under the Master Repurchase Agreement (MRA) that governs most trades, collateral is marked to market every day. If the market value of the securities drops below the required level, the lender can issue a margin call. The borrower then has a set period, typically two business days, to post more cash or securities and close the gap.⁵ Daily recalibration keeps the loan fully collateralized even in fast-moving markets.

Tri-Party or Bilateral

Open repos are executed in one of two operational formats. In a bilateral repo, the two parties deal directly. They agree on terms, exchange cash and securities, and manage settlement and collateral themselves. This gives more control but demands substantial back-office capacity.

In a tri-party repo, a third-party agent, typically a government securities clearing bank in the U.S. market, sits between the parties. The agent takes custody of the securities, settles the cash and collateral exchange, values the collateral daily, and allocates it efficiently using optimization tools.⁶ Clearing banks also extend intraday credit to dealers so they can meet delivery obligations. Large institutions tend to prefer tri-party for its operational reach. The open-ended rollover mechanics work the same way in either format.

Ending an Open Repo

Closing an open repo requires one party to formally call the trade. That means notifying the counterparty that the agreement will end during the next settlement cycle. The notice period is set in the trade documentation, and standard practice is a morning cutoff for same-day settlement.¹

Once called, the borrower returns the cash principal plus any accrued interest that has not yet been settled, and the lender simultaneously returns the pledged securities. Electronic settlement systems complete both legs together. Both sides verify the final numbers before the transfer is recorded. This clean exit is a large part of the appeal: an institution can walk away on any business day without breaching a contract.

Risks Specific to the Open Structure

Open repos are among the safer short-term instruments available, but a few risks come with the open-ended design.

Interest rate risk. The rate resets daily against the benchmark or resets when the parties renegotiate. Borrowers have no forward certainty about funding costs. A sudden rate spike can double borrowing costs overnight. In mid-September 2019, quarterly tax payments and a large Treasury settlement drained more than $100 billion in bank reserves over two days, pushing SOFR above 5% on September 17 until the New York Fed intervened with an emergency overnight repo operation. Anyone with an open repo outstanding that morning felt the reset immediately. A term repo would have locked in the earlier rate.⁷
Rollover risk. Either side can terminate on any business day. A cash lender that calls the trade forces the borrower to find replacement funding right away, potentially at a worse rate. In stressed markets, several lenders may pull back at once.
Counterparty risk. If the borrower defaults, the lender must sell the collateral to recover the loan. Liquidating large positions quickly can mean selling at a discount, especially for non-Treasury collateral. If the haircut did not fully absorb the price drop, the lender takes a loss.
Collateral concentration. A repo book backed almost entirely by one type of security faces correlated risk. If that asset class falls, margin calls hit across the whole portfolio at the same time.

These exposures are manageable in ordinary conditions. They compound during exactly the moments when markets are least able to absorb them.

Bankruptcy Safe Harbor

One legal feature makes repos attractive to institutional lenders in ways an unsecured loan never could be. Under federal law, if a repo counterparty files for bankruptcy, the non-defaulting party can immediately liquidate the collateral and terminate the agreement. The bankruptcy court’s automatic stay, which normally freezes creditor action against a debtor, does not apply.⁸

The safe harbor comes with a fairness condition. If the lender liquidates the collateral and the proceeds exceed what the borrower owed (the repurchase price plus liquidation expenses), the excess must be returned to the bankruptcy estate. The Bankruptcy Code defines a “repurchase agreement” broadly enough to cover transactions in Treasury securities, agency debt, mortgage-related securities, certificates of deposit, and qualifying foreign government securities, with maturities up to one year or payable on demand.⁹ Being able to seize and sell the collateral immediately, regardless of the borrower’s bankruptcy filing, is a large reason lenders accept thin or even zero haircuts on Treasury repos.

How Repos Are Booked and Taxed

Despite the “sale” and “repurchase” language, most repos are treated as secured borrowings rather than true sales for both accounting and tax purposes. The borrower keeps the pledged securities on its balance sheet, and the cash received shows up as a liability.

Under FASB’s accounting standards (ASC Topic 860, Transfers and Servicing), the test is whether the transferor has maintained “effective control” over the transferred securities. A standard repo includes an obligation to repurchase the same or substantially identical securities, so the transferor typically retains effective control and the transaction is booked as a financing.¹⁰ Tax treatment follows the same logic. Because the economic substance is a collateralized loan rather than a genuine transfer of ownership, the “sale” leg does not trigger a taxable gain or loss. Interest paid by the borrower is interest expense; interest received by the lender is interest income.

1
International Capital Market Association. Frequently Asked Questions on Repo – 12. What is an Open Repo?
2
Federal Reserve Bank of New York. Secured Overnight Financing Rate Data
3
Federal Reserve Bank of New York. An Updated User’s Guide to SOFR
4
Office of Financial Research. Are Zero-Haircut Repos as Common as Advertised?
5
U.S. Securities and Exchange Commission. Master Repurchase Agreement
6
Federal Reserve Bank of New York. Frequently Asked Questions – The Tri-Party Repo Market
7
Federal Reserve Board. What Happened in Money Markets in September 2019?
8
Office of the Law Revision Counsel. 11 U.S. Code 559 – Contractual Right to Liquidate, Terminate, or Accelerate a Repurchase Agreement
9
Office of the Law Revision Counsel. 11 USC 101 – Definitions
10
Financial Accounting Standards Board. FASB Issues Accounting Standards Update to Improve Financial Reporting of Repurchase Agreements