The trading strategy used is bollinger bands. (You can create bollinger bands on graphs in poloniex). The strategy is to buy when price touches lower bollinger band and sell when the price is above your bought price and also hits high bollinger band. If the price goes down and again touches lower bollinger band then invest another 25% of total investment assigned for a currency.
These are what allow us to buy and sell cryptocurrencies. There are a handful of popular crypto exchanges, some of them have advantages over others. For example, some exchanges don’t allow us to deposit and withdraw using fiat currency like the U.S. dollar and euro; others aren’t available in certain countries. In this guide we will focus on two very popular exchanges, GDAX and Poloniex. GDAX gives us the ability to use our fiat currency to buy Bitcoin. Poloniex does not, but does give us a wide array of altcoins to trade. There, we’ll be using major coins like Bitcoin and Ethereum to buy the altcoins, and vice versa. Other popular exchanges such as Kraken and Bittrex offer even more coins.
Always pay attention to Bitcoin. Most altcoins (every cryptocurrency except Bitcoin) are pegged more closely to Bitcoin than Asian currencies were to the USD during the Asian Financial Crisis. If Bitcoin price pump drastically, altcoins price can go down as people try to exit altcoins to ride the BTC profits; inversely, if Bitcoin prices dump drastically, altcoin prices can go down, too, as people exit altcoins to exchange back into fiat. The best times for altcoin growth appear when Bitcoin shows organic growth or decline, or remains stagnant in price.