In simple terms, the Gap Trading Strategies are a rigorously defined trading system that uses specific criteria to enter and exit. Trailing stops are defined to limit loss and protect profits. The simplest method for determining your own ability to successfully trade gaps is to paper trade. Paper trading does not involve any real transaction. Instead, one writes down or logs an entry signal and then does the same for an exit signal. Then subtract commissions and slippage to determine your potential profit or loss.