I personally think the fundamentals for trading cryptocurrencies is to first of all have it at the back of your mind that you have to follow the rules that “you buy low and sell high” meaning that you buy at a low price and sell at a higher price,then the. Next step is to be able to meausre the demand and supply on the market,check the volume of transactions to know whether more people are buying into the market or people are leaving the market,the more people are buying in the market the higher the price will keep going and that is the best time to sell your cryptos,if people are leaving the market by selling off then the more the price will keep going down