Errors and warnings

What if a swap is detected as a deposit?

Last reviewed: August 15, 2026

If a swap lands as a deposit and a withdrawal, the exchange is missing. The outgoing side becomes a sale without proceeds, or the inflow arrives without cost basis. Both distort the gain. The cause is almost always an on-chain or Ledger import that only sees transfers, not the economic swap.

The facts in brief
Symptom	A deposit and withdrawal instead of a swap
Effect	A fake sale and cost basis 0
Fix	Book both sides as one swap

How do you recognise the error?

Two movements in the same minute, opposite assets, often plus a fee. In the tool they sit as deposit/withdrawal. Economically it was ETH for USDC or an LP event. The same pattern appears with token merges and wraps.

Why is this dangerous for tax?

An unrecognised swap either hides a disposal or invents one. In Germany crypto-to-crypto is generally taxable. At the same time the new coin gets no cost basis. The next sale becomes a full gain.

How you assign it correctly

1) Mark both sides and the fee as one swap. 2) Set the market value at the time of the exchange. 3) Check that balance and cost basis then close. In chain.report that is a CleanUp step for smart contracts.

Frequently asked questions

Does this only happen with Ledger?

Ledger is common because it often only shows inflows and outflows. Any chain wallet without a decoder can produce the same error.

Is wrapping ETH/WETH also a swap?

Treat it deliberately. Either as a change of form with a continuing history or as an exchange — but not as two independent transfers.

Can I just delete the two rows?

No. Then the event is missing entirely. You must represent it as an exchange, not remove it.