What means "missing cost basis" in the tax report?

If the Coinfox tax report indicates "missing cost basis", it points to incomplete transaction data. Specifically, this means that for one or more sales the original purchase was not recorded – the acquisition cost of these coins is therefore unknown. Without this information, Coinfox cannot calculate a correct profit/loss. The most common cause for this is that not all wallets or exchanges were included. Solution: Check if you have recorded all transactions. Add any missing wallets/exchanges and their transaction history so that there is a corresponding purchase (with cost basis) for each sale. Then you can regenerate the tax report, and the error message should disappear.