Profit factor is your gross profit divided by your gross loss. Above 1 means you made money, and most tradeable systems land between 1.2 and 2. It is a quick health check, not an edge. A handful of outlier winners can inflate it, a tiny sample can fake it, and it says nothing about drawdown or how often the result repeats. Read it next to expectancy and trade count, never alone.
Profit factor is the sum of your winning trades divided by the sum of your losing trades, both as positive numbers. A profit factor of 1.5 means you made 1.50 for every 1.00 you lost.
Anything above 1 made money over the sample. Most real retail systems sit between 1.2 and 2. A profit factor under 1 means the losses outweighed the wins, and a number like 4 on a small sample is almost always a warning rather than a trophy.
Between 1.2 and 2 for most tradeable systems. Higher is not automatically better, because it is so easy to inflate.
A profit factor of 3 across 1,000 trades is a serious result. The same 3 across 30 trades is noise, and one across 50 trades carried by two giant winners is a single lucky streak. The number means nothing without the trade count and the shape of the winners sitting next to it.
Because it can be inflated by a few outliers and says nothing about risk. Edge is whether the result repeats; profit factor is just a ratio of two sums.
Strip out your three best trades and watch a profit factor of 2.5 fall to 1.1, and you have learned the edge was three trades, not a system. Profit factor also ignores drawdown entirely, so two strategies with the same profit factor can put you through wildly different pain. It is a smoke alarm, not a diagnosis. For the number that actually measures the edge, see expectancy.
Quantprove shows profit factor as one metric among many, but it never lets it carry the grade. Your Edge Score weighs expectancy, consistency, downside, and tradability, and discounts the whole thing for small samples.
That is deliberate. A clean profit factor on 40 trades should not earn the same trust as a modest one on 800, and only sample aware scoring tells them apart. Profit factor gets you curious; the score tells you whether to believe it. To check the result is not luck, run it through is your edge real or luck and watch why a high win rate can still lose money at the same time.