SYSTEM: PYRAMIDING
A common theme among successful traders such as Jesse Livermore and Richard Dennis (The Turtles) is that of maximizing a position when you are correct. This ensures that your winners will exceed your losers by a fair margin and allow you to profit, even if your winning percentage is less than 50%. Position sizing must be approached carefully, though, and always within your risk guidelines.
After the initial entry, I pyramid my position every 0.5ATR once price has moved 1.0ATR in my favor. At each 0.5ATR increment, I add 1/2 the initial number of contracts. I will pyramid up to 5ATR, at which point I consider myself to be position limited. The reason I begin at 1.0ATR is that I use a trailing stop of 2.0ATR using the Chandelier method (subtract/add 2.0ATR from the most recent price high/low). Assuming I entered with N contracts at an initial stop of 2ATR, and I add 0.5N contracts when price has moved to 1.0ATR, my risk maxes out at 3ATR. This is in contrast to the Turtle style (for example), where they added the same number of contracts at 0.5ATR increments. This would result in larger winners because you really piled on in the initial stages, but does lead to increased exposure. There is always the chance of a large reversal in the first initial stages, of course, but this is offset somewhat by the fact that you are slowly building your position and one of the main reasons I do it in this fashion.
I consider this to be a fair compromise between the "pedal-to-the-metal" Turtle method, and hamstringing your winners by adding on too slowly.
As my trades progress, I'll show some charts with pyramiding in action to demonstrate the method.