If you are living in any of these countries then you should go ahead and start a cryptocurrency business as you will pay zero tax for trading, holding and on your earnings.
1. Iran
2. Portugal
3. Malaysia
4. Singapore
5. Malta
6. Belarus
7. Germany
8. Switzerland
I am only aware of the above eight if your country falls in this list then do comment or if you are in a country, where every transaction get taxed. I am trying to compile a list.
You did not mention the countries in Asia. As far as I know, there are a few countries in Asia that collect cryptocurrency tax like Korea, Japan, Thailand .. And there will certainly be more