If you sell a cryptocurrency, you usually make a capital gain or a capital loss. This is the difference between what it cost you to acquire the crypto and the price when you dispose of it. This could be when you trade one cryptocurrency for another on an exchange (eg BTC => ETH), trade a cryptocurrency to fiat (eg BTC => USD) or when you make a purchase using cryptocurrency. Also when fees are paid, gains on the fee amount is accounted for.
Transferring crypto between your own accounts is not classed as a taxable event and these transfers will not effect your short to long-term holds.
Upon starting Moonie for the first time, you will be asked to choose a Cost Layering Method. The selected method will determine how Moonie calculates capital gains. An example method is First In, First Out (FIFO). This method means that, of a given cryptocurrency, you sell your oldest holdings first and newest holdings last. You should consult with your accountant/tax advisor prior to selecting a cost layering method.