Quote from PoundTheRock:
Pedro, performance reports for scalping systems (5-minute time frames or less) are extremely deceptive, especially breakout systems where slippage is a greater consideration. Fills and spreads are everything. Slippage of a penny on either side can blow what appears to be an extremely profitable system out of the water. Watch the system in real-time for a few days and then simply try it. Can you pull off the executions? For example, I developed a system that traded blocks of large-cap tech with a holding period of 10 minutes, profit factor in the mid 2's. The system turned me to jelly, the executions were so difficult to pull off, and those misses sabotaged the performance.
