Why do two swaps of the same amount on the same site give different received amounts

05 September 2026

The short answer: market rates move constantly, network fees vary by congestion, and the swap provider's internal inventory and liquidity sources can change between two attempts. You are never swapping against the same conditions twice.

Even a few seconds between two swaps of the same amount can produce different received amounts. The price of any cryptocurrency on an exchange or aggregator is not a single fixed number. It is the last price at which someone bought and someone sold. That number changes every time a trade happens anywhere. between your first click and your second, a hundred trades may have occurred across the markets the swap provider uses. The rate you see is a snapshot. It is not a guarantee.

Network fees also shift. The fee to move a token on Ethereum, for example, is not set by the swap site. It is set by the network's own auction for block space. When many people are sending transactions, fees rise. When the network is quiet, fees fall. A swap that routes through a busy chain at one moment may show a higher deduction than the same swap five minutes later on a calmer chain. The swap provider passes that cost through. It does not control it.

The swap provider itself may be drawing liquidity from different pools or order books at different times. Aggregators split a trade across several sources to get the best combined rate. The exact mix of those sources can shift between attempts. One source may have been drained by a large trade between your two swaps. The next best source may offer a worse rate. The result is a different received amount for the same face value.

Another factor is the spread the provider builds into its quote. That spread is not always flat. It can widen when the provider's own inventory is thin, or when market volatility increases. It can narrow when liquidity is abundant. Between your two swaps, volatility may have spiked or eased. The provider adjusts its spread accordingly. You see the result as a different final amount.

Slippage tolerance also plays a role. If you set a tolerance of 0.5 percent on the first swap, the transaction will execute as long as the rate does not worsen by more than that amount. If the market moves against you during that transaction, you get a rate near the edge of your tolerance. On the second swap, the market may have moved in your favor. The same tolerance then locks in a better rate. The difference is not the site cheating you. It is the market moving while your transaction waits for confirmation.

Finally, the swap site itself does not guarantee that two identical requests will follow the same routing path. Its algorithm may decide that a different route is optimal a moment later, even if the quoted rate looks similar. The route determines the fees and the final amount.

If you want to understand the full breakdown of where every fraction of your swap goes - spread, network fees, and the gap between quoted and received - read the hub page "What a crypto swap actually costs." It explains the components that produce the number you see at the end.

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