LIBOR was a family of unsecured term bank-funding benchmarks; all settings have ceased, but legacy contracts and historical analysis still require careful fallback review.
LIBOR, the London Interbank Offered Rate, was a family of benchmark interest rates intended to represent the cost at which large banks could obtain unsecured wholesale funding for specified currencies and maturities. All 35 LIBOR settings have now ceased permanently, but the benchmark remains relevant to historical data, legacy contracts, litigation, accounting records, and transition analysis.
LIBOR was not one rate. In its final panel-bank configuration, the family combined five currencies with seven maturities, producing settings such as three-month U.S. dollar LIBOR and six-month sterling LIBOR.
LIBOR was designed as an unsecured bank-funding benchmark. Panel banks submitted rates for specified currencies and maturities, and the administrator calculated a trimmed arithmetic mean after excluding high and low submissions.
The final standardized family covered:
The seven maturities ranged from overnight to twelve months. The exact panel, methodology, administrator, and available settings changed over LIBOR’s history, so an analyst working with old data should verify the rules that applied on the observation date.
A floating-rate coupon was commonly expressed as:
The margin compensated the lender or investor for risks and economics not represented by the benchmark. A fixed margin did not make the total rate fixed because the LIBOR component reset periodically.
A document also had to specify:
The label “LIBOR plus 150 basis points” is therefore incomplete without the contract’s definitions.
Assume a legacy USD 25 million note used three-month U.S. dollar LIBOR plus a 1.40% margin. For a 90-day Actual/360 period, suppose the valid historical LIBOR fixing was 5.20%.
The annualized all-in rate was:
Illustrative interest was:
After cessation, an analyst cannot simply insert one day’s SOFR into the same formula. The contract may require a term SOFR setting, compounded SOFR, a statutory replacement, and a separate spread adjustment. It may also change the observation timing.
Two problems converged.
First, enforcement cases showed that submissions could be influenced to benefit derivatives positions or portray a bank’s borrowing conditions more favorably. The LIBOR Scandal page explains those conduct and governance failures.
Second, the market for unsecured wholesale term borrowing by banks became too shallow to support every currency-and-maturity setting with a deep stream of eligible transactions. Judgment therefore played a larger role precisely where a widely used benchmark needed a strong market foundation.
The Financial Stability Board promoted reform of major benchmarks and the development of nearly risk-free overnight alternatives. Regulators and market working groups then coordinated a multi-year transition.
Most panel-bank LIBOR settings ended after 2021, while selected U.S. dollar panel settings continued temporarily to support transition. The FCA also required temporary synthetic LIBOR settings for certain legacy uses where contracts could not transition smoothly.
Synthetic settings used changed methodologies and were formally unrepresentative of the markets the original settings had sought to measure. They were transition tools, not a revival of panel-bank LIBOR or benchmarks for new business.
The final synthetic one-, three-, and six-month U.S. dollar settings ceased after publication on September 30, 2024. The FCA states that this ended LIBOR overall.
| Feature | LIBOR | SOFR | SONIA | €STR | TONA |
|---|---|---|---|---|---|
| Status | Discontinued | Active | Active | Active | Active |
| Currency role | Historical multi-currency family | U.S. dollar | Sterling | Euro | Japanese yen |
| Maturity of primary rate | Historical overnight and term settings | Overnight | Overnight | Overnight | Overnight |
| Underlying market | Unsecured term bank funding submissions | Secured Treasury repo | Unsecured sterling wholesale deposits | Unsecured euro wholesale borrowing | Uncollateralized yen call transactions |
| Longer-period use | One term fixing commonly set the period | Daily compounding, averages, index, or permitted term form | Usually daily compounding; limited term use | Daily compounding, averages, or index | Daily compounding, averages, or term-derived form |
The replacement benchmark can have less bank-credit and term-liquidity content than LIBOR. A fallback spread attempts to address part of that economic difference; it does not make the two benchmarks identical.
This article provides general financial education, not personalized investment, borrowing, accounting, tax, or legal advice. Use the governing contract and current official administrator or regulator publications for any live calculation or dispute.