A very very good point - someone opening up a tax compliant crypto exchange and being successful. I would definitely open up an account with that exchange that would do all the calculations for me (just like any ordinary online stock trading exchange would) so I never have to dread being audited by the IRS on my crypto currency trades - knock on wood! Oh I just wanted to add that in South Korea (one of the most active crypto currency trading hot pots in the world) one does not have to pay any capital gain tax when trading crypto currency. This is probably one of the reasons why South Koreans account for heavy percentage of all trading even though their total population is about 1 / 7 of that of the US.