Win rate tells you how often you win. Risk-to-reward ratio tells you how much you make when you win relative to what you lose when you don't. Both are useful — but neither one, on its own, tells you whether your strategy actually makes money over time.
Expectancy is the metric that combines them. It answers one specific question: on average, how much do you make or lose per trade?
That number is the most direct measure of whether your trading strategy has a genuine edge. A positive expectancy means the strategy is profitable over a large enough sample. A negative expectancy means it loses money over time, regardless of how disciplined your execution is.
The expectancy formula
Expectancy is calculated from four inputs you can pull directly from your trading journal: your win rate, your loss rate, your average winning trade, and your average losing trade.
Expectancy = (Win rate × Average win) − (Loss rate × Average loss)
Where: win rate is the percentage of trades that closed at a profit (e.g. 0.45 for 45%); loss rate is 1 minus win rate; average win is the mean dollar value of your winning trades; average loss is the mean dollar value of your losing trades (use a positive number).
The result is your expected average profit or loss per trade. A positive number means the strategy has a positive edge. A negative number means it doesn't.
A worked example
Say a trader has the following statistics from the last 100 trades: win rate 45%, loss rate 55%, average winning trade $350, average losing trade $180.
Expectancy = (0.45 × $350) − (0.55 × $180) = $157.50 − $99.00 = +$58.50 per trade.
Over 100 trades, the strategy is expected to produce around $5,850 in net profit — before variance, which always exists in the short term.
Now look at what happens when the average loss increases from $180 to $280 while everything else stays the same: Expectancy = (0.45 × $350) − (0.55 × $280) = $157.50 − $154.00 = +$3.50.
Expectancy collapses to $3.50 per trade. The strategy is technically still positive — but fees, slippage, and any deterioration in win rate or average win would push it negative quickly. This is how traders end up with a decent win rate but flat or losing P&L: the losses are too large relative to the wins.
Why win rate alone is misleading
Consider three traders:
Trader A — High win rate, negative expectancy: Win rate 72%, average win $80, average loss $310. Expectancy = (0.72 × $80) − (0.28 × $310) = $57.60 − $86.80 = −$29.20. Wins nearly three quarters of trades and is still losing money.
Trader B — Low win rate, positive expectancy: Win rate 38%, average win $620, average loss $200. Expectancy = (0.38 × $620) − (0.62 × $200) = $235.60 − $124.00 = +$111.60. Loses nearly two thirds of trades and has a strong positive expectancy.
Trader C — Moderate win rate, thin positive expectancy: Win rate 55%, average win $210, average loss $190. Expectancy = (0.55 × $210) − (0.45 × $190) = $115.50 − $85.50 = +$30.00. Technically profitable, but with a narrow enough margin that costs and bad weeks can easily tip it negative.
None of this is visible from win rate alone. Expectancy shows it immediately.
Positive vs. negative expectancy
A strategy with positive expectancy will produce net profits over a large enough sample of trades, assuming consistent execution. A strategy with negative expectancy will lose money over time regardless of short-term luck. No amount of position sizing, discipline, or risk management can make a negative-expectancy strategy profitable in the long run. If your expectancy is negative, the only real fix is to change the strategy — improve your average win, reduce your average loss, or increase your win rate.
Positive expectancy doesn't guarantee profitable months. Variance means you can have a run of losses even with a strong edge. But over hundreds of trades, positive expectancy is what separates strategies that work from those that don't.
How to improve your expectancy
Expectancy has three levers. Understanding which one is pulling your number down tells you exactly where to focus.
Lever 1 — Increase your average win
This often means letting winning trades run further instead of exiting too early. Many traders compress their average win by locking in gains quickly out of fear the trade will reverse. If your average win is consistently smaller than your planned take profit, exit discipline is the first place to look.
Lever 2 — Reduce your average loss
This means honoring your stop loss consistently. Every time you move a stop further out, widen your risk, or hold a losing trade past your planned exit, your average loss grows. In most trading journals, the average loss is the number with the most room for improvement — and the one most directly controlled by rule-following rather than market conditions.
Lever 3 — Improve your win rate
This means being more selective about which trades you take. Reducing low-quality setups — trades taken out of boredom, FOMO, or unclear reasoning — typically improves win rate without requiring any change to the core strategy. Crucially, these levers interact. Trying to improve win rate by exiting winners earlier might increase profitable trade count but compress your average win, hurting expectancy overall. Any change to one variable should be evaluated against the full formula.
Expectancy vs. profit factor
Expectancy and profit factor are related but answer slightly different questions. Expectancy measures the average dollar profit or loss per trade — useful for understanding the absolute value of your edge and projecting P&L. Profit factor measures the ratio of gross profit to gross loss — useful for comparing strategies regardless of position size. When both metrics point in the same direction, you have more confidence in the edge. When they diverge, it's worth investigating why.
How to use expectancy in your trade review
Expectancy is most useful as a trend metric — something you calculate regularly and watch over time. In your weekly trade review, check whether your expectancy is stable, improving, or declining. A falling expectancy usually has a specific cause: average losses have grown (stop discipline has slipped), average wins have shrunk (exiting too early), or win rate has dropped (taking lower-quality setups). The formula tells you which lever moved.
It's also worth calculating expectancy separately by strategy. A mixed strategy book often has one strong-expectancy setup carrying the overall number and one or two setups with weak or negative expectancy dragging it down. Separating them gives you a clear picture of where your actual edge lives.
TheSpeculatorsJournal calculates expectancy automatically from your trade data — alongside win rate, profit factor, average R:R, and the rest of your analytics. You can also filter by strategy or emotional state to see how expectancy varies across different conditions. Start a free 7-day trial and see your own numbers without building a single formula.
A note on sample size
Expectancy calculated from a small number of trades can be very misleading. Ten trades is not enough. Twenty trades is not enough. A single large outlier win or loss will skew the average figures, producing a number that looks nothing like the strategy's real long-term behavior. As a practical guideline, most traders need at least 50 to 100 trades in similar market conditions before their expectancy figure becomes meaningfully stable.
FAQ
What is a good expectancy in trading?
Any positive expectancy is a real edge. The size depends on your strategy, position sizing, and trade frequency. A scalper taking 30 trades a day can sustain a much smaller per-trade expectancy than a swing trader taking 5 trades a week. What matters is that the number is positive and stable over a meaningful sample.
Can I have a positive expectancy but still lose money?
Yes, in the short term. Variance means that even a strategy with strong positive expectancy will have losing weeks and months. The expectancy figure represents the long-run average — it doesn't eliminate drawdown periods. This is why sample size matters: a positive expectancy is only reliable when calculated across enough trades to smooth out short-term variance.
Is expectancy the same as expected value?
They're the same concept. Expected value is the mathematical term used in probability and game theory; expectancy is the same calculation applied to trading. The formula and interpretation are identical.
Should I calculate expectancy in dollars or as a ratio?
Both are valid. Dollar expectancy is more intuitive for evaluating real-world profitability and projecting future P&L. R-multiple expectancy — where wins and losses are expressed in units of risk rather than dollars — is more useful for comparing strategies across different position sizes. If you always risk the same fixed dollar amount per trade, both calculations tell the same story.
Does a higher win rate always improve expectancy?
Not automatically. If you increase your win rate by exiting winners earlier, your average win decreases at the same time. Depending on the magnitude of the change, expectancy can stay flat or even fall despite a rising win rate. Any change to your trading rules should be evaluated against the full formula, not just the win rate figure in isolation.
Conclusion
Expectancy is the metric that ties everything together. Win rate tells you how often you win. Risk-to-reward ratio tells you the relative size of your wins and losses. Expectancy combines both into a single number that answers the only question that ultimately matters: does this strategy make money over time?
Calculate it from your journal data. Watch it over time. When it moves, use the formula to find out which lever changed. That feedback loop — between your trade data and your understanding of where your edge actually lives — is what makes the difference between traders who improve and traders who stay stuck.
This article is for educational purposes only and is not financial advice. Trading involves risk, and past performance does not guarantee future results.