Yes, that amounts to 20,000 times 4, which equals 80,000 in undeclared earnings. This could result in approximately 20,000 in taxes owed (assuming they were capital gains and not income tax) plus a fine of up to an additional 20,000. Overall, it’s not an excessive amount.
It's not uncommon for authorities to discover undeclared earnings and subsequently send notices or requests to electronic money institutions (EMIs) and providers like Nexo, if the accounts are linked to your ID via KYC providers. Not uncommon neither to request Onfido, AMLBot and Sumsub, in which EMIs and exchanges you validated your ID
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