Investing in any currency is an activity that, roughly speaking, can be done in two ways: the speculative, by means of short sales (buying and selling currencies several times in one day depending on the possibilities of the price going up or down), Or by developing a medium- or long-term investment scheme (i.e buying currencies and saving them for a longer period to sell them when appropriate).
To be able to take short positions, we need to understand margin trading. Trading on margin means we are trading with borrowed money. On exchanges like Poloniex, we can trade Bitcoin with a handful of coins (there are fewer coins offered for margin trading) with 2.5x leverage. That is, if we own 1 BTC, we can borrow up to 2.5 BTC to trade with. To be clear, this is not 2.5 BTC that we own. Now, on a trade that nets us 10% profit, we are bringing home .25 BTC instead of .1 BTC.
U.S. Government Required Disclaimer - Commodity Futures Trading Commission. Futures and options trading has large potential rewards, but also large potential risk. You must be aware of the risks and be willing to accept them in order to invest in the futures and options markets. Don't trade with money you can't afford to lose. This website is neither a solicitation nor an offer to Buy/Sell futures or options. No representation is being made that any account will or is likely to achieve profits or losses similar to those discussed on this website. The past performance of any trading system or methodology is not necessarily indicative of future resultsĀ 
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.