Is Trading Coins Legal or Not?
Illegal but not against the law
If all your deposits and withdrawals are legitimate, then just pay some taxes in the end.
However, there are currently too many illegal activities, and if you're not careful, you might get taken for a 'tea' (interrogation).
Anyway, you can't prove a lot of things, and sometimes when faced with a crackdown, you get labeled, the money disappears, and you end up in jail.