I think it would be correct to answer this question by thinking about two different situations. In the first case we will examine anonymous wallet owners. How will they tax an unshared purse on the Internet or any stock exchange? This wallet will not be taxed unless it is really an idea of the owner of that wallet. But if you look at the second case, yes, taxation will be possible because the wallet account in this case will be shared by the owner on the internet or this information will be exported to some stock exchange sites. In this way the state will be able to acquire the wallet and tax on these gains.