Most of the time i buy them at exchanges. When new cryptocurrencies hit the exchanges they always tank first. I personally have used this system with over a dozen currencies and notice a hockey stick pattern. The currency drops upon release and bottoms out. At this point you simply buy up some cryptos and hold until dumping. I personally grab up some cryptos and dump when I hit a 20% profit. I sometimes hold the currencies for a longer period and sell them for an even higher profit. Remember trading cryptos is a game of entries and exits. The trick is to get in early and sell at a profit.