Fixed or floating rate: lock the price when the chain is slow or the market is moving
A floating rate settles at execution, so the amount you receive can move with the market between the quote and execution, which happens only after your deposit confirms. A fixed rate locks the price for a set window, 20 minutes on SimpleSwap, in exchange for a slightly wider spread.
A swap rate that is locked for a set window after you create the order, 20 minutes on SimpleSwap, so the amount you receive does not move with the market during that window. CoinMarketCap Academy notes the trade-off: the user may pay a higher fee for it.
What is the difference between a fixed and a floating rate?
A quoted rate is only a snapshot of a moving market, as 1inch puts it. Every completed swap changes pool reserves, and crypto prices can rise or fall over short periods.
The two rate types decide who carries that movement while your order is in progress.
Floating rate
- The price settles at execution.
- What you receive can move up or down between the quote and execution.
- No lock window to watch.
- Good for: fast deposit chains and calm markets.
Fixed rate
- The price is locked for a set window.
- The lock costs a slightly wider spread.
- Good for: slow deposit chains and moving markets.
See the difference on your own numbers
Enter the amount you are quoted and drag the slider to move the market. The floating bar follows the market; the fixed bar stays where it was locked.
Why does a fixed rate usually cost more?
When a service locks a rate, it takes on the risk that the market moves before your deposit confirms. That risk is priced into the quote.
CoinMarketCap Academy describes this directly: a fixed rate removes slippage, and the trade-off is that the user may have to pay a higher transaction fee.
On SimpleSwap the lock lasts 20 minutes and comes with a slightly wider spread.
Why did the rate change before my swap completed?
On a floating rate, the swap executes only after your deposit is confirmed. How long that takes depends on the chain you send from.
- ~10 minaverage gap between Bitcoin blocks, with no guaranteed minimum or maximumbitcoin.org
- 12 sEthereum slot time, with one block proposed per slotethereum.org
- 3 sTron block intervaldevelopers.tron.network
- ~2 minMonero block timegetmonero.org
A slow first confirmation leaves more time for the market to move.
Bitcoin.org also notes that a transaction paying a fee below what the network is prioritising may take considerably longer to confirm.
Which should you pick?
Answer two questions and the widget suggests a rate type.
- Check the deposit chain
Fast chains confirm in seconds. Bitcoin can take ten minutes or more for one block.
- Look at the market
If prices are moving fast, a lock protects the amount you receive.
- Compare both quotes
Note what each one says you receive. The fixed quote may start a little lower.
- Send within the window
With a fixed rate, send the deposit straight away so it arrives inside the lock.
How SimpleSwap and ChangeNOW offer it
- SimpleSwap: fixed and floating rates; a fixed rate is locked for 20 minutes. It publishes a 99.998% estimate-accuracy figure for most floating swaps.
- ChangeNOW: fixed and floating rates.
Lock windows of other services are in the fixed-rate list. To measure what happened on a past floating swap, use the slippage calculator.
Questions
What is the difference between a fixed and a floating exchange rate?
A floating rate settles when the swap executes, so the amount you receive can move with the market.
A fixed rate is locked for a set window after you create the order, 20 minutes on SimpleSwap.
Why does a fixed rate usually cost more?
The service carries the risk that the market moves during the lock, and that risk is priced into the quote.
CoinMarketCap Academy notes that a user may pay a higher fee for a fixed rate.
Why did the rate change before my swap completed?
A quote is a snapshot of a moving market. On a floating rate, the swap executes only after the deposit confirms, and prices can move in the meantime.
How long is the SimpleSwap fixed rate locked?
20 minutes.
What is an instant crypto swap?
An instant swap converts one cryptocurrency into another in a single order, with no fiat step: you send from your wallet and the service delivers the other asset to your address.