Expectancy — P&L
Expected value per trade in account currency. Average net P&L across all trades.
- Computed from
- Trades list
- Scope
- Single report
- Range
- Any real number
- Direction
- Higher is better
Expectancy is the bottom line of a trading edge: the average amount you can expect to make (or lose) per trade, over many trades. It rolls win rate and payoff ratio into one number — and if it's positive, the system makes money in the long run.
How it's calculated
Expectancy = (Win% × AvgWin) − (Loss% × AvgLoss)
= mean(net P&L per trade)- Win% / Loss%
- share of winning / losing trades
- AvgWin / AvgLoss
- average size of a win / a loss (loss as a positive magnitude)
What it tells you
Expectancy is the per-trade "edge." Combined with how many trades you take, it gives a first-order estimate of expected income:
Expected weekly result ≈ Expectancy × trades per week
This is an estimate, not a forecast — it assumes the edge, the trade frequency, and the position sizing all keep holding (see Pitfalls).
Worked example
A system wins 45% of trades, with an average win of +$300 and an average loss of −$180:
Expectancy = 0.45 × 300 − 0.55 × 180 = 135 − 99 = +$36 per trade
At 40 trades a week that averages to roughly +$1,440/week — but read that as a long-run mean, not a paycheck. The real path swings hard around it: losing streaks are normal, and a positive-expectancy system can still ruin an over-sized account before the average ever shows up. It also assumes the historical edge keeps working (see Pitfalls).
Pitfalls
- It's a rear-view mirror. Expectancy is measured on trades that already closed. A positive number is evidence of a past edge, not a promise of a future one — edges decay as markets, crowding, and spread conditions change. The more recent and the more numerous the sample, the more you can lean on it; a thin or stale record projects poorly.
- An average hides the variance — and the risk of ruin. A positive expectancy still comes with losing streaks, and bad sizing can ruin the account before the long-run average ever arrives. Size positions so you survive the streaks (see Kelly).
- Driven by outliers. A handful of huge winners can carry expectancy; if they don't repeat, the edge evaporates. Cross-check profit concentration — and check when the edge shows up, since a system that earns its whole year in a few sessions is far harder to trade than its expectancy suggests.
- Costs scale with frequency. The ×trades multiplier in the projection multiplies costs too — slippage and spread that look tiny per trade add up at 40 trades/week, and live fills rarely match a clean historical record.
- Which version you use matters. The $-version weights big positions more; the return-% and pips% versions ignore position size. Use the size-neutral versions when comparing strategies.
Expectancy vs profit factor
Both summarize the trade distribution. Profit factor is a ratio (total wins ÷ total losses, scale-free); expectancy is an amount (per-trade, in real units). Profit factor tells you the edge's quality; expectancy times frequency tells you the edge's size in money.