I have a vague idea of the tax situation for CGT re: crypto; but it's confusing. The %15 tax on gains seems acceptable; but, from what I can see, it seems that is based on the sale price. One can sell at a loss; so what then? Does the exchange still withhold %15. It would seem fairer to calculate the CG based on the actual gain. If that were to be the case, then how would the cost base be assessed? If I were to return to my home country and re-establish residency for tax purposes, then the cost base of my holdings would be assessed at the price on the day of return to my country. i.e. "deemed acquired". But how does it work in Thailand? If, for example, I have some BTC that I bought a long time ago when not a resident of Thailand, would it be assessed as bought then? If so how would I provide proof of purchase price? Or is the purchase price somehow calculated upon the date of becoming a resident here?