What is cost basis and sale proceeds

Hello,

Can you please tell me how the cost basis and sale proceeds are calculated by your software. Does the cost basis include fees as well? Does the sale proceed exclude fee? Thanks

The value of our coins are fetched from CoinMarketCap.

I am also interested in this question from @Jajan.

Somehow I can’t shake the feeling that the fees associated with buying a coin are not included in the cost basis. I have prepared this super simple albeit artificial example.

How can the cost basis for selling be 90€ if we had 10€ fees at purchase (only the selling fees are considered?)

This leads to the wrong overall gains (10€) instead of the correct 0€ …

Would appreciate any help.