Fixed vs Floating Rate in Crypto Exchange: Which One Should You Pick?

The short version: what's the difference

A crypto swap is never instant. Between the moment you see the rate and the moment your coins reach the service and get confirmed on-chain, minutes pass, sometimes an hour. The market doesn't stand still in the meantime. The rate type answers one question: who carries that price movement.

In a nutshell: with a floating rate you take the market risk and pay less. With a fixed rate the service takes the risk, and in return you pay a bit more and play by its rules. VertEXchange offers both: it's a no-KYC crypto exchange, and you switch the rate type right in the exchange form.

How a floating rate works

With a floating rate, the form shows an amount based on the current market, but it's a calculation, not a promise. The final rate is set when the service receives your funds. If the coin you're sending goes up in the meantime, you get more. If it drops, you get less.

On the exchange page you'll see "floating rate" in the header and a line saying "Send ..." without the word "exactly". Next to it runs a countdown, "Order valid for ... more": that's how long the order lives, not a rate window, and it can be long, up to several days.

What you should know:

• The shift is usually small. In a calm market the rate moves a fraction of a percent over 10 to 30 minutes. But on days of sharp moves, like the night Zcash fell 12%, the difference becomes noticeable.
• The rate in the form lives for two minutes. If you take longer to decide, the form says "Rate is outdated — refreshing" and shows a fresh amount.
• A big move can pause the exchange. If by the time your transfer arrives the rate has drifted too far from the quote, the exchange may stop with the note "The rate moved too far between the quote and the arrival of the transfer." Your money doesn't vanish: it's either exchanged at the new rate or refunded.
• The amount you send is flexible. Sent a little more or less than you entered? The result is simply recalculated, as long as the amount stays within the pair's limits.

Floating is the default in the form: it's cheaper, and twice as many coins support it.

How a fixed rate works

With a fixed rate, the amount you receive is frozen the moment the exchange is created. You get exactly what you saw on the exchange page, even if the market drops 5% in the meantime.

But the guarantee comes with conditions:

1. A short window. Under the deposit address on the exchange page there's a countdown, "Rate locked for ... more". It's usually about 15 minutes, and the exact time is shown on the page. Your transfer has to arrive within it.
2. The exact amount. Instead of "Send" it says "Send exactly ...". Not more, not less, and in a single transfer: a fixed-rate order accepts only one.
3. Not for every coin. A fixed rate is available for roughly half of all coins. If a pair doesn't support it, the form switches the type for you and says "This pair has a floating rate only".

When the window runs out, the address and QR code disappear from the page and you'll see "The sending window has closed" instead.

If you're late or send the wrong amount

This is the main catch with a fixed rate. The exchange stops for such transfers, and the page explains why:

• "The transfer arrived after the order had expired."
• "The amount sent did not match the order."
• "A fixed-rate order accepts only one transfer."

Your money isn't lost in these cases: it's sent back to your refund address, and if you didn't give one, the page will ask for it. But a refund costs time and another network fee. That's why it's best to enter a refund address right away, when you create the exchange.

A common reason for being late is a low network fee. Your wallet sent the transaction, but it's stuck in the queue and the window closes. Send with a normal fee, and you can always check a transaction by its hash in a block explorer.

How much the guarantee costs

A fixed rate costs more because the service takes on the price risk for the length of the window and builds it into the rate. On the popular BTC to ETH pair, the difference in our tests was about 0.5% of the amount received. On rare and volatile coins it's higher; on stablecoin-to-stablecoin swaps it's close to zero.

Checking the difference for your own pair is easy: switch the rate type in the form, and the amount you receive updates instantly, before you create the exchange.

Which rate to choose

Go with floating if:

• you're swapping one stablecoin for another, for example to move USDT from ERC20 to TRC20: their prices barely diverge, so there's no point paying for a guarantee;
• the market is calm and you want the best rate;
• you're sending from an exchange where withdrawals can be held for review, and 15 minutes may not be enough;
• the pair simply has no fixed rate.

Go with fixed if:

• you need an exact amount on the other side, say you're paying an invoice or topping up a specific balance;
• the market is moving hard right now and you don't want to guess what you'll get;
• you're swapping a volatile coin for a stable one, for example to convert bitcoin to USDT TRC20 on the day of a big drop;
• you're sending from your own wallet and know you'll make the window.

For large amounts in a volatile market, 0.5% for the guarantee is often cheaper than a possible half-hour price swing. For small swaps in a calm market, there's no reason to overpay.

How to avoid mistakes

• Check the rate type before creating the exchange. It's shown in the header of the exchange page.
• With a fixed rate, send right away. Created the exchange? Send the funds now, not "in half an hour".
• Copy the amount, don't round it. With a fixed rate, 0.01 and 0.0100001 are different amounts.
• Account for the exchange's withdrawal fee. If you send from an exchange, it may deduct its fee from the amount, and less than required will arrive. With a fixed rate, that's a mismatch.
• Enter a refund address. It comes in handy whenever something goes wrong.
• Don't forget the memo. XRP, TON and Stellar also need a memo or Destination Tag, or your transfer won't be matched.

For example, to swap bitcoin for ether on VertEXchange, open the pair, enter the amount and flip the rate type: you'll see right away what the guarantee costs at this moment.

FAQ

Which is better: a fixed or a floating rate?

On average, floating: a fixed rate has the cost of the guarantee built in. But if the market moves against you during the swap, fixed turns out cheaper. Nobody knows that in advance.

How long does a fixed rate last?

Usually about 15 minutes. The exact time counts down on the exchange page: "Rate locked for ... more".

What happens if I send more or less with a fixed rate?

The exchange stops with the note "The amount sent did not match the order.", and the funds go back to your refund address. With a floating rate, the result is simply recalculated.

I sent my coins too late. Is my money gone?

No. A transfer that arrives after the window is refunded to your refund address. Sometimes such an exchange goes to manual review, and it's then either processed or refunded.

Why doesn't my pair have a fixed rate?

Not every coin and network has enough liquidity to keep a rate guaranteed. In that case the form only offers a floating rate.

Can a floating rate change in my favor?

Yes. If the coin you sent goes up during the swap, you'll get more than you were shown.