Most swap providers offer a choice between fixed and floating rates, and the option you pick can noticeably change what you end up with on the other side of the transaction. Neither is universally better — they’re suited to different situations.
How a fixed rate works
A fixed rate locks in the exchange price at the moment you confirm, typically holding for a short window — often somewhere around 15 to 30 minutes depending on the provider. Whatever the market does during that window, you get the rate you locked in. The trade-off is usually a slightly wider spread, since the provider is absorbing the risk of market movement on your behalf.
How a floating rate works
A floating rate tracks the live market right up until your transaction settles. If the market moves in your favor between quote and execution, you benefit; if it moves against you, you get less than the quoted estimate. Floating rates typically carry a narrower spread, since the provider isn’t taking on that same volatility risk.
When each makes sense
- Choose fixed when you want certainty — you know exactly what you’ll receive, which matters more during high volatility or for larger transactions where a price swing would meaningfully change the outcome.
- Choose floating when markets are relatively calm and you’re more focused on getting the tightest possible spread than on locking in certainty.
The practical takeaway
Neither option is a trick or a hidden cost — they’re two legitimate ways of handling the same underlying problem: markets move between the moment you get a quote and the moment your transaction settles. Knowing which trade-off you’re choosing means the outcome is never a surprise.

