In the US it seems the taxes for cryptocurrency can be complex. You should expect that you have to pay SOME tax on your cryptocurrency otherwise the IRS might come looking for you! I tried to read into it via the IRS but it's pretty confusing. It seems to be they want you to report EVERY gain/lose when trading cryptocurrency. They expect it to be recorded so it can be verified I presume? I also believe that an income tax is expected from the profits of your cryptocurrency when turned into fiat currency. It's a real mess...I think the IRS is asking for tips/suggestions regarding cryptocurrency but I don't know where exactly you would go to email/mail them.