A good trade can lose money, and a bad trade can make money. Even the best trading processes will lose a certain percentage of the time. There is no way of knowing a priori which individual trade will make money. As long as a trade adhered to a process with a positive edge, it is a good trade, regardless of whether it wins or loses because if similar trades are repeated multiple times, they will come out ahead. Conversely, a trade that is taken as a gamble is a bad trade regardless of whether it wins or loses because over time such trades will lose money.
-Jack Schwager
