This is an update to the earlier post I posted. See second paragraph below: I ran a few backtests on several simple systems and keep getting the same results - no matter how low I set the trailing stop or the stop loss, I never get stopped out more often, even if it's set to $0.01 loss on one contract. What I mean is that if you're trading an S&P contract, and for example, the tighter the stop (especially as low as 1 cent on over 20k contract), the more trades should show as losers as you'd get stopped out more often, and the total profit should at some point start declining. Instead, when I run the program, the profit gets higher the tighter the stop is (even as tight as 1 cent), and the amount of losing trades does not change. The systems get into the trade and get out on the same day. It looks like the software does not use intradey tick data, but rather plots a straight line from day's open to low to high to close or from open to high to to low to close and uses this 'immitated' price data to do the backtesting. This is the only way I can explain not being stopped out more often with a $0.01 stop loss vs. $200 stop loss on one S&P contract. I use $100 for commission and slippage on every trade and for the trailing stop. I sell if price goes down a certain amount using either: Code: Highest High in Trade - Dollars to Price (Trailing Stop Amount) OR: Code: Highest High in Trade - Range Any clue as to what's going on? Thanks so much. -John