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What is Prime Rate?

The prime rate is the interest rate that commercial banks charge their most creditworthy corporate customers, used worldwide as the benchmark from which retail loan and credit-card rates are derived by adding a risk premium.

Although 'prime rate' is best known as the US benchmark (US Prime = Federal Funds Target + 3 percentage points), every major banking market has an equivalent reference rate. In Switzerland, retail mortgage and consumer-loan rates are quoted as 'SARON + X%' or as a flat fixed rate set by the bank's treasury. In the eurozone, variable rates often reference Euribor; in the UK, the Bank of England Base Rate.

For retail customers the prime rate matters because most variable-rate debt is priced as a spread over it. A credit card priced at 'Prime + 12%' will increase by exactly one percentage point when the central bank raises Prime by 100 basis points. Conversely, fixed-rate loans are unaffected during their fixation period — one of the main reasons borrowers lock in long fixed terms when rates are low.

Track the trajectory of the policy rate rather than the absolute level. A 4% Prime rate that is on its way down to 2% is more borrower-friendly than a 3% Prime rate climbing toward 5%. Major central-bank meetings (SNB quarterly, ECB and Fed every six weeks) are the calendar events that move the curve.

Example

A Swiss household holds a credit card priced at 'SARON + 11%'. SARON rises from 0.5% to 1.5% over a year, lifting the card APR from 11.5% to 12.5%. On a CHF 3,000 average balance that increases annual interest cost by CHF 30.

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Frequently asked questions

How is the US Prime rate set?+

By a survey of major US banks; it is typically Federal Funds Target Rate + 3 percentage points.

Does Switzerland have a prime rate?+

Not by name — banks quote retail rates relative to SARON, Libor (legacy) or their own internal cost of funds.

How often does the prime rate change?+

Whenever the central bank moves the policy rate, plus occasional discretionary changes by individual banks.