Common US ARMs are described as 5/1 or 7/1: a 5- or 7-year fixed period followed by annual adjustments tied to SOFR or another index. Caps limit how much the rate can move per adjustment and over the life of the loan.
In Switzerland, the equivalent is the SARON-based mortgage, which resets every 1 or 3 months based on the overnight rate — fully variable from day one. ARMs are attractive when interest rates are expected to fall or when the borrower plans to sell before the first adjustment.
Beispiel
A US borrower takes a 5/1 ARM at 4.5%; for years 1–5 the rate is fixed, then each year it resets to SOFR + 2.25%, with caps of 2% per adjustment and 5% over the life of the loan.