so we assume there will be tax ? eventhogh it is not automatic will there be a taxation ? how do you declare your income and tax in this situation.
For just holding coins over one year with no sales in between there should be no 25% tax, but at this volumes there might be the question with regards to your status as a privat person or a company trading so there might be some tax implications.
Automatic taxtation does exist in Germany and many banks support it (unless you give them a "Freistellungsauftrag") by directly sending of the text parts on your trades. But as banks do not see your coins, do not really consider coins, and can not know about the duration of your holding, this is not applicable here and is more for shares and interest on bank accounts.
If you are a German citizen you just file your tax report and declare your wins and losses and then beg to not get audited. I have no experience with the process for foreign citizens. Having said all that at this amount of Fiat it might be worth to shell out a few bucks for a tax advisor ("Steuerberater"), there are actually some with cryptocurrency experience.