Profit Factor: The One-Number Summary of a Strategy's Edge

Profit factor = gross profit ÷ gross loss. Add up everything the winning trades made; add up everything the losing trades lost; divide. A profit factor of 1.0 means the strategy broke even before costs. Above 1.0, the wins outweighed the losses; below it, the strategy lost money.

The formula, worked

Say a backtest produced 40 winners averaging $120 and 60 losers averaging $70. Gross profit = 40 × $120 = $4,800. Gross loss = 60 × $70 = $4,200. Profit factor = 4,800 ÷ 4,200 = 1.14. Note the strategy wins only 40% of the time and is still profitable — profit factor is exactly the number that reconciles win rate with the size of wins and losses.

What is a good profit factor?

• Below 1.0 — losing strategy. No position-sizing trick fixes it.
• 1.0 to 1.3 — thin edge. Real, but fragile: a small rise in spread or slippage can erase it. Check the strategy's costs assumptions carefully.
• 1.3 to 2.0 — a solid edge for a systematic strategy, if the sample is large (hundreds of trades) and the test was honest.
• Above 3 — be suspicious before you are pleased. Very high profit factors usually mean a tiny sample, an overfit parameter set, or a backtest that looked into the future. Verify on an independent engine before believing it.

Profit factor's blind spots

Profit factor says nothing about sequence. A strategy can post 1.6 and still bury you in a drawdown, because it says nothing about how the losses cluster — that is what maximum drawdown measures. It also says nothing about trade frequency: 1.5 over eight trades a year and 1.5 over eight hundred are very different businesses. Always read profit factor next to sample size, drawdown, and expectancy per trade.

ForexEdge reports profit factor on every backtest alongside those companions, and the same statistic follows the strategy through TradingView verification and live demo trading — so you can watch whether the edge measured in the lab survives contact with reality.