No need to fully understand bitcoin trading. With the money you earned from mining, just buy 1 and watch it quadruple in value after a couple of years.
Well trading is good too for get another profit on bitcoin, mining is not take much time though. You can use your free time to learn trading and also you need to sell your bitcoins too right. So when you get profits from mining, you can use your time to trading and trading also let you know the bitcoin price and other altcoins price.