“If you buy Bitcoins at one price and then sell them for a higher price, you make a profit of the difference between those two prices, less any commission that you paid. However, if the price goes down, you will be in the uncomfortable position of having to either sell them at a loss or hold and hope the price goes back up while risking higher and higher losses if the price continues to drop.”

Depending on what you mean by "trade," there are plenty of tempting reasons to break into the world of bitcoin trading. Having done your research on bitcoin, you may think it has peaked and that if you sell your coins now you'll make the best profit you can. Maybe you're intrigued by a new cryptocurrency on the rise and want to trade some of your bitcoins for it, diversifying your portfolio of cryptocurrencies. Or you could just want out of the bitcoin game and have decided it's time to sell it all.
Bitcoin trading really is not much different to any other asset you can trade - maybe just a bit more volatile, but that is a good thing if you want to trade it! You will have to devide whether or not to trade the asset (bitcoin) itself or some derivative (financial “bet”). I recommend the latter as it allows you to participate in both bull and bear markets. If you simply buy the asset (Bitcoin) you can only participate in rising prices. The derivative also allows you to leverage your position. Having that said : LEVERAGE IS A DOUBLE SIDED SWORD! Whenever you trade with leverage make sure you are mentally ready to lose everything that is on your trading account (in other words: make sure not to put too much money on your trading account). Moreover, do not trade something you do not understand!
The receiver of the first bitcoin transaction was cypherpunk Hal Finney, who created the first reusable proof-of-work system (RPOW) in 2004.[22] Finney downloaded the bitcoin software on its release date, and on 12 January 2009 received ten bitcoins from Nakamoto.[23][24] Other early cypherpunk supporters were creators of bitcoin predecessors: Wei Dai, creator of b-money, and Nick Szabo, creator of bit gold.[25] In 2010, the first known commercial transaction using bitcoin occurred when programmer Laszlo Hanyecz bought two Papa John's pizzas for 10,000 bitcoin.[26]