SOFR (Secured Overnight Financing Rate)
SOFR (Secured Overnight Financing Rate) is the preferred U.S. dollar interest rate benchmark administered by the Federal Reserve Bank of New York, measuring the cost of borrowing cash overnight collateralized by U.S. Treasury securities in the repo market. SOFR replaced LIBOR as the primary U.S. dollar reference rate following LIBOR's discontinuation at end of June 2023, and serves as the index for trillions of dollars of floating-rate loans, bonds, derivatives, and mortgages.
Key takeaways
- SOFR is a transaction-based, nearly risk-free rate, in contrast to LIBOR which was a bank credit-risk-inclusive term rate susceptible to manipulation — a distinction that affects pricing of credit products.
- Daily SOFR is published by the NY Fed each morning based on the prior day's overnight Treasury repo market transactions, which total approximately $1 trillion daily — making it among the most liquid reference rate markets in the world.
- SOFR is an overnight rate and lacks a forward-looking term structure; Term SOFR (1-month, 3-month, 6-month), published by the CME, was developed to serve as a LIBOR-like term rate for loans that require advance knowledge of periodic interest payments.
- SOFR-based derivatives (SOFR futures and SOFR overnight index swaps) have become deeply liquid since 2022, providing reliable hedging instruments for corporate borrowers and financial institutions.
- The spread adjustment embedded in the ISDA LIBOR-to-SOFR fallback protocols (~26 bps for 3-month LIBOR to 3-month Term SOFR) compensates for the credit premium that was embedded in LIBOR.
Explanation
The transition from LIBOR to SOFR represents the most significant benchmark reform in the history of global financial markets, affecting an estimated $200 trillion in financial instruments denominated in U.S. dollars. LIBOR (London Interbank Offered Rate), the predecessor benchmark, was a panel-based rate submitted by major banks representing their estimated unsecured borrowing costs — a methodology that proved vulnerable to manipulation (culminating in billions of dollars of regulatory fines) and increasingly unrepresentative of actual market transactions as interbank unsecured lending contracted sharply after the 2008 financial crisis.
SOFR's methodology is fundamentally different. It is a volume-weighted median of overnight repo rates in three segments of the U.S. Treasury securities repo market: tri-party repo (excluding GCF repos), bilateral repo cleared through FICC's DVP service, and GCF repos. The NY Fed publishes SOFR each morning at approximately 8:00 AM Eastern Time. Because it is anchored in over $1 trillion of actual daily transactions, it is highly resistant to manipulation and accurately reflects prevailing secured overnight financing conditions.
The key difference between SOFR and LIBOR has important pricing implications. LIBOR embedded bank credit risk — it reflected the rate at which banks could borrow from each other unsecured, which rises significantly during financial stress. SOFR is essentially risk-free (backed by U.S. Treasuries), so it does not spike when bank credit risk rises. This makes SOFR-indexed loans cheaper during normal periods but potentially misaligned with the actual funding costs of bank lenders during crises. Industry participants use credit sensitive alternative rates (like AMERIBOR or BSBY, though BSBY was discontinued in 2023) for some commercial lending applications.
The practical adoption of SOFR across different product types has followed different paths. For derivatives (interest rate swaps, futures), the market shifted substantially to SOFR by end of 2021. For business loans, the use of Term SOFR — the CME-published forward-looking term rates based on SOFR derivatives markets — provided borrowers and lenders with the certainty of knowing interest payment amounts in advance, mimicking LIBOR's behavior. For mortgage-backed securities and structured products, the transition required case-by-case amendment or utilization of embedded fallback language.
For fixed-income portfolio managers and hedge fund rate traders, SOFR's nearly risk-free nature has implications for the construction of hedging strategies. A floating-rate bond indexed to SOFR has different interest rate risk and credit risk characteristics than a comparable LIBOR-indexed bond. Duration and DV01 calculations must account for the compounding mechanics of SOFR (daily compounded in arrears for bonds, versus simple interest for term rate loans). SOFR swaps are the primary instrument for managing duration exposure in the short end of the U.S. yield curve.
Formula
SOFR Compounded in Arrears = [∏(1 + SOFRᵢ × dᵢ/360) - 1] × 360/D
Example
A corporation issues a $500 million, 3-year floating-rate note paying Term SOFR (3-month) + 125 basis points, reset quarterly. At issuance, Term SOFR is 5.30%, so the initial coupon is 6.55%. If Term SOFR falls to 4.50% by the second reset, the coupon adjusts to 5.75%. The CFO simultaneously enters a pay-fixed/receive-SOFR interest rate swap with a notional of $500 million at a fixed rate of 5.10%, effectively converting the floating-rate obligation to a fixed all-in cost of 6.35% (5.10% + 125 bps spread) — locking in borrowing costs regardless of future SOFR movements. The hedge relationship is documented under FASB ASC 815, qualifying for fair value hedge accounting treatment that limits income statement volatility from mark-to-market movements in the swap.
Related terms
Amortizing Bond Basis Bond Collateralized Debt Obligation Credit Risk Duration Dv01 Financial Crisis Hedge Fund Hedging High Yield Bond Implied Repo Rate