Trading metric
Profit factor
Profit factor is the cleanest single-number verdict on a trading system: how many dollars it made for every dollar it lost. Above one, you are ahead. The interesting part is what the number hides.
What it is
Profit factor is gross profit divided by gross loss over a set of trades. Make 8,000 in winners and lose 4,000 in losers, and your profit factor is 2.0 — two dollars earned for every dollar given back. A profit factor above 1.0 is profitable; below 1.0 is a losing system.
It is popular because it compresses win rate and trade size into one ratio that is hard to game with a good week. Where win rate can flatter a losing account, profit factor reflects the actual dollars in and out, so a system with small frequent wins and rare large losses cannot hide behind a high hit rate.
The catch is concentration. A single enormous winner can lift profit factor to a number the strategy cannot repeat, and a single catastrophic loss can sink an otherwise sound one. Profit factor is most honest over many trades where no one result dominates the totals.
How to measure it
Sum the wins, sum the losses, divide. The only judgment calls are the sample window and whether costs are included — and they should be.
Profit factor = gross profit ÷ gross loss (absolute value)
- 1
Choose the trade sample — a strategy, a date range, or your whole account.
- 2
Add up every winning trade to get gross profit, net of commissions and fees.
- 3
Add up every losing trade (as a positive total) to get gross loss, also net of costs.
- 4
Divide gross profit by gross loss. Above 1.0 is profitable; the further above, the more cushion.
- 5
Check whether one or two trades dominate either total — if so, the ratio is fragile and needs a larger sample to trust.
Worked example
Over 80 trades you make 12,000 in gross profit and lose 6,000 in gross loss, for a profit factor of 2.0. Then you notice one trade contributed 7,000 of that profit. Strip it out and the profit factor falls to about 0.83 — a losing system carried by a single outlier. Same headline number, completely different reality once you look underneath.
What good looks like
As a rough guide, a profit factor between 1.3 and 1.6 is a workable edge, 1.6 to 2.0 is solid, and above 2.0 is strong — but only over a large, varied sample. Numbers far above 2 on a small or short sample usually signal curve-fitting or a lucky outlier rather than a robust system.
The healthier read is stability across conditions. A profit factor that holds near 1.5 through trending and choppy markets is more valuable than one that prints 3.0 in a single favorable regime and collapses when conditions change.
Below 1.0
A losing system over the sample. The gross losses outweigh the gross profits — the edge or the execution needs to change.
1.3 – 2.0
The realistic working band for a durable discretionary edge. Solid, repeatable, and not dependent on a single trade.
Above 2.0 on a small sample
Treat with suspicion. Often an outlier win or an overfit backtest rather than a strategy you can lean on.
What moves it
One outlier carrying the ratio
A lone giant winner can make a mediocre system look elite, and a lone giant loss can sink a good one. Always check whether the totals survive removing the single largest trade on each side.
Ignoring costs
Profit factor computed before commissions and fees overstates the edge, and the overstatement is worst for high-frequency styles. Net costs out or the number is a marketing figure, not a measurement.
Overfit backtests
A strategy tuned until its historical profit factor looks spectacular is usually fitted to noise. The live number lands far lower, which is why out-of-sample and forward testing matter more than the backtested ratio.
A few large losses from broken discipline
Holding losers past the stop creates the occasional outsized loss that wrecks gross loss and tanks the ratio. The fix is behavioral — honoring the stop — not a different strategy.
How Mettle tracks it
Mettle computes profit factor from your imported fills, net of the costs you record, and keeps the underlying trades one click away so you can see whether the ratio is real or rests on a single outlier.
Gross profit and gross loss are summed from logged fills, so profit factor updates automatically as you trade.
Because every trade links to its page, you can spot the outlier carrying the ratio instead of trusting the headline number.
Filtering by play or date range shows whether the profit factor holds across conditions or depends on one favorable stretch.
When a broken stop produces an outsized loss, the review prompts you to tag it, connecting the dented ratio to the behavior behind it — tags you report yourself.
FAQ
What is a good profit factor?
Over a large sample, roughly 1.3 to 1.6 is a workable edge, 1.6 to 2.0 is solid, and above 2.0 is strong. Very high numbers on small or short samples usually mean an outlier trade or an overfit backtest rather than a robust system. Stability across market conditions matters more than the peak value.
What is the difference between profit factor and expectancy?
Profit factor is the ratio of total dollars won to total dollars lost; expectancy is the average profit per trade. Profit factor answers "how efficient is the system overall," while expectancy answers "what is one trade worth." They agree on the sign of the edge but describe it from different angles.
Does Mettle calculate this automatically or do I report it?
The number itself is arithmetic on your logged fills, so Mettle computes it for you on the dashboard. What stays self-reported is the behavioral side — the tags and execution notes you add in review — because only you know whether you followed the plan. The copy never pretends otherwise.
Is Mettle free to start?
Yes. You get full access free for 14 days with no card. We only ask for a card once you have reviewed three sessions — after the product has proven it earns a place in your routine.
Check whether your profit factor is real
Mettle computes profit factor from your fills and keeps every trade one click away, so you can see whether the ratio holds up or leans on a single outlier.
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Want the workflow behind the numbers? Read the matching guide.