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.

Bitcoin trading occurs on exchanges. These exchanges accept your fiat currencies (like USD and EUR) in exchange for a cryptocurrency (like BTC). These exchanges maintain a liquid pool of bitcoin, allowing users to withdraw their bitcoin at any time. Investors who wish to trade on that exchange can deposit bitcoin into their personal wallet on the exchange, or make a wire transfer to the exchange’s bank account. The exchange notices this transfer, then credits your account.
Never put all your eggs in one basket. Diversify. While the potential to earn more is increased with the amount of money you invest into a coin, the potential to lose more is also magnified. Another way to think about it is to look at the cryptocurrency market as a whole; if you believe that this is just the beginning, then more than likely the entire market cap of cryptocurrencies will increase. What are the chances that this market cap increase will be entirely driven by one coin vs. being driven by many coins? The best way to safely capture the overall growth of cryptocurrency is to diversify and reap the benefits of growth from multiple coins. Also, fun fact — Between January 2016 and January 2018, Corgicoin has increased by 60,000x, and Verge has increased by 13,000x. During the same period, Bitcoin has increased by 34x. While you would have gotten impressive gains from Bitcoin, expanding into other coins could have landed you potentially larger ones.