Failed Swaps: What You Pay for a Transaction That Reverts

Transactions fail. The cost of a failure depends entirely on where in the process it happened.

Failure on chain

A transaction that reverts still consumed network resources and still pays the network fee. Nothing is received and the fee is gone.

Common causes: slippage tolerance set too tight, insufficient fuel for the work required, or a price that moved past the limit during confirmation.

Failure at the venue, before execution

A quote that expired or a balance check that failed. Usually costs nothing, because nothing was submitted.

This is the benign case and the most common one.

Failure at the venue, after execution

Rare and expensive. The conversion completed and the payout did not, usually because of a compliance hold or an operational problem.

The assets exist and are held. Resolution is a support process rather than a technical one, and a venue with a published conversion schedule operating under a licence gives you an escalation path that an anonymous one does not.

Partial fills

An order that filled half and cancelled the rest. You hold a position half the intended size and have paid costs on both the filled portion and, in some fee structures, the attempt.

Worth checking whether your venue charges on attempted or filled quantity. The two differ and it is in the schedule.

The slippage tolerance trade

Set it tight and transactions fail more often, each failure costing a network fee. Set it loose and they succeed at worse prices.

Neither is free. The right setting depends on how expensive failure is on your network, which is the flat-versus-proportional calculation again.

What to record after a failure

The error, the fee paid, and the state afterwards. Most failures repeat, and a record of three similar failures usually reveals a setting rather than bad luck.

The structural fix

Convert where failure is handled by the venue rather than by the chain. An internal conversion at an exchange either happens or does not, and a failed one costs nothing.

Platforms that show slippage before confirmation reduce the first category by letting you see the problem before submitting, and Collect & Exchange, where the quote holds for the whole amount, removes the price-moved-during-confirmation failure entirely.