An overnight loan provides funds for repayment on the next business day, commonly for wholesale liquidity and settlement management.
An overnight loan is very short-term financing advanced for repayment on the next business day under the transaction’s settlement and business-day rules. Banks and other financial institutions use overnight funding to manage payment flows, reserve balances, securities settlement, and unexpected liquidity needs.
“Overnight” describes maturity, not one standardized product. The exposure may be an unsecured federal funds transaction, another wholesale deposit or loan, a securities-backed repurchase agreement, or qualifying central-bank credit. Their counterparties, collateral, rates, legal form, and risks differ.
A basic unsecured transaction follows this sequence:
The transaction can be arranged bilaterally or through a broker. Documentation may be a master agreement, deposit confirmation, platform rulebook, or other market contract. Cutoff times and payment-system availability are important because a funding trade that fails to settle may not solve the original liquidity need.
Assume a bank borrows $50 million overnight at an annualized rate of 3.75% using Actual/360. If the accrual covers one calendar day:
$50,000,000 x 3.75% x 1 / 360 = $5,208.33
The borrower repays $50,005,208.33 at maturity.
If the same contractual convention applies from Friday to Monday and interest accrues for three calendar days:
$50,000,000 x 3.75% x 3 / 360 = $15,625.00
Actual settlement calendars, holidays, rate conventions, and compounding rules can differ. “Overnight” does not always mean exactly 24 hours or one day of interest.
Federal funds transactions are unsecured U.S.-dollar borrowings by depository institutions from other eligible institutions and entities, commonly overnight. The transferred balances are held at Federal Reserve Banks.
The effective federal funds rate (EFFR) is a transaction-based measure calculated and published by the Federal Reserve Bank of New York. An individual federal funds trade can occur above or below the EFFR because of counterparty, timing, size, and market conditions.
The New York Fed’s Overnight Bank Funding Rate (OBFR) is broader than the EFFR. It incorporates federal funds transactions plus certain Eurodollar and domestic deposit transactions reported by banks.
OBFR is a market measure, not a universal contractual rate. A bank’s actual overnight funding cost depends on the eligible instrument and counterparties it can access.
A repo transaction is a sale of securities with an agreement to repurchase them later. Economically, it resembles secured borrowing: cash is advanced against securities, and the difference between sale and repurchase prices reflects financing cost.
Repo terms also include collateral eligibility, valuation, haircut, margin maintenance, substitution, custody, and closeout rights. An overnight repo and an unsecured overnight loan can have the same maturity but materially different recovery and operational risks.
The Federal Reserve’s discount window lends directly to eligible depository institutions against collateral. Primary credit can be available overnight or for a term of up to 90 days under current program terms.
Discount-window borrowing is therefore not synonymous with an overnight loan. It has its own eligibility, collateral, rate, documentation, and operational requirements.
| Rate | Market measured | Secured? | What it is not |
|---|---|---|---|
| EFFR | Overnight federal funds transactions | No | The rate on every interbank loan |
| OBFR | Federal funds plus specified Eurodollar and domestic deposits | No | A secured financing rate |
| SOFR | Broad overnight Treasury repo financing | Yes | A measure of unsecured bank credit risk |
| Primary credit rate | Federal Reserve discount-window program | Collateral required | A private-market transaction median |
These rates can move together as monetary policy and liquidity conditions change, but their levels and behavior need not be identical. Credit risk, collateral, eligible counterparties, transaction coverage, and calculation methodology differ.
An institution may need overnight funds to:
The short maturity can be efficient for a temporary mismatch. It is a weak solution for a persistent structural funding gap because the borrower must repeatedly refinance.
| Feature | Unsecured overnight loan | Overnight repo |
|---|---|---|
| Primary support | Borrower’s credit and legal obligation | Borrower/counterparty credit plus securities and closeout rights |
| Pricing inputs | Credit, liquidity, relationship, timing, market rates | Collateral quality, haircut, scarcity, term, counterparty, market rates |
| Asset movement | Cash or deposit/reserve balance | Cash and securities settle under repo terms |
| Main operational need | Funding and repayment instructions | Funding, collateral valuation, custody, margin, and substitution |
| Loss path after default | General claim under the agreement | Collateral liquidation and closeout, subject to documentation and market value |
Collateral reduces some credit exposure but does not eliminate loss. Price gaps, wrong-way risk, settlement failure, legal defects, concentration, and illiquid collateral can impair recovery.
Analysts should confirm:
A one-day delay can be economically material on a large principal. It can also create settlement risk if one side transfers value before receiving the expected counterpayment.
Central banks influence overnight money-market rates through administered rates, reserve balances, open-market operations, and standing facilities. In the United States, the Federal Open Market Committee sets a target range for the federal funds rate, while the New York Fed implements policy and publishes transaction-based reference rates.
This does not mean every overnight loan is made at the target range or EFFR. Market access, collateral, institution type, credit, timing, and stress conditions affect transaction pricing.
The New York Fed also conducts repo and reverse repo operations for monetary-policy implementation and market functioning. Those official operations should not be conflated with private bilateral loans merely because both can mature overnight.
Calling repo an ordinary loan without qualification. It is legally documented as a sale and repurchase while functioning economically as collateralized financing.
Treating EFFR, OBFR, and SOFR as synonyms. They measure different secured and unsecured transaction sets.
Assuming overnight means one calendar day. Weekends and holidays can extend accrual.
Assuming short maturity means low risk. Credit duration is brief, but settlement and rollover risk can be immediate.
Using another overnight loan as the repayment plan. Renewal can fail during institution-specific or market-wide stress.
Treating discount-window credit as always overnight. Primary credit can also be term funding under current program rules.
Overnight borrowing is primarily an institutional wholesale-market concept. This article provides general financial education, not individualized liquidity, lending, legal, regulatory, accounting, or investment advice.
Official U.S. sources were reviewed on September 1, 2026.