Ask a trader how their strategy is doing and they will tell you their win rate. It is the wrong number.
Win rate feels like the scoreboard because it is the part that feels good: you were right seven times out of ten, so surely you are making money. But win rate says nothing about how much you win when you are right or how much you lose when you are wrong, and those two numbers decide everything. A strategy that wins 70% of the time can bleed an account dry, and a strategy that loses 60% of the time can be a quiet money machine. The number that tells the two apart is expectancy, and once you have it, you stop guessing whether your edge is real.
This is what trading expectancy is, how to calculate it in one line, why it exposes strategies that win rate flatters, and how to keep the edge you find from leaking away in costs and sizing. Everything here runs on your own trade history, so it is only as honest as your records; if you are not logging every trade yet, that is the real first step.
Expectancy is the average amount you can expect to make, or lose, per trade over a large number of trades. It rolls win rate, average win, and average loss into a single figure. If it is positive, the strategy makes money over time. If it is negative, the strategy loses money over time, no matter how good any individual week looks.
The formula is short:
Expectancy = (Win rate × Average win) − (Loss rate × Average loss)
Where the loss rate is simply 1 minus the win rate. The result is a dollar figure per trade: what one average trade is worth to you, good and bad outcomes blended together.
That single number is the whole game. It says: across the next hundred trades I take with this strategy, this is roughly what each one is worth to me on average. Everything else — the hot streaks, the cold streaks, the one that got away — is variance around that figure.
Here is the comparison that makes expectancy click. Two traders, wildly different win rates, and the loser is the one you would expect to be winning.
Trader A wins only 40% of the time. When they win they make $600; when they lose they lose $200 — a clean 3:1 payoff. Trader B wins 70% of the time, which sounds far healthier, but they make $100 on a win and lose $300 on a loss, because they cut winners early and let losers run.
Trader A, wrong more often than right, makes $120 on an average trade. Trader B, right seven times in ten, loses $20 on an average trade. Run each of them a hundred times and Trader A is up $12,000 while Trader B is down $2,000, and Trader B spends the whole time feeling like the better trader because the wins land more often. This is exactly why a high win rate can still lose money — a trap we pull apart from the risk/reward side in why your 1:3 risk/reward ratio is still losing money. Win rate is one of two inputs. On its own it tells you almost nothing.
Dollars are fine when your position size never changes, but the moment you trade different sizes the dollar figure gets noisy. The fix is to measure expectancy in R — multiples of the amount you risk on a trade. If you risk $200 on a trade, that $200 is 1R. A $600 win is +3R; a $200 loss is −1R.
Expressed that way, Trader A's expectancy is +0.6R per trade: every time they pull the trigger, they earn six tenths of what they risked, on average. That number travels. It holds whether you are risking $50 or $500, it lets you compare two strategies on equal footing, and it plugs straight into how you size, which is the whole point of getting position sizing right in the first place. Most serious journals track expectancy in R for exactly this reason.
The quick read on an R figure: anything above 0 makes money over time. Around +0.1R to +0.3R is a real, workable edge that compounds if you trade it enough. Above +0.5R is strong. Negative is a strategy you are paying to run, however good it feels on the winning days.
An edge per trade is only half the picture. What builds the equity curve is expectancy multiplied by how often you get to use it. A +0.3R edge taken twice a month and a +0.3R edge taken forty times a month are not remotely the same business.
So the real driver is expectancy × number of trades. This is also why "trade less" and "trade more" are both bad blanket advice. If your expectancy is positive, more quality trades is more money — but only the quality ones, because forcing extra trades usually means taking worse setups that drag the average down and quietly flip the edge negative. That is the mechanism behind overtrading: not that volume is bad, but that the marginal forced trade almost always has worse expectancy than the ones your rules actually asked for.
The formula is easy. Getting a number you can trust is where it goes wrong. These four are what turn a comforting figure into a misleading one.
Expectancy over twenty trades is noise, not a measurement. A couple of lucky wins or one bad run swings it wildly. You want a sample in the hundreds before you trust the figure, and until then you treat it as a rough sketch, not a verdict. This is the same sample-size discipline that decides whether a strategy actually works or is just in a normal drawdown.
If a single monster win is holding your whole expectancy up, you do not have an edge, you have a lottery ticket that happened to hit. Strip out your biggest win and recalculate. If the number collapses or goes negative, the strategy is not really positive — it got rescued once. Real edges survive the removal of any single trade.
Spread, commission, and swap come out of every trade, and a thin positive edge can go negative once they are counted. Expectancy calculated on gross prices is a fantasy number. Use your actual fills, fees included, or you are measuring a strategy you are not the one trading.
A single expectancy figure across every setup, session, and instrument hides the truth. One profitable setup can carry the whole average while a bleeder rides along unnoticed underneath it. Split the number by setup and by session and you often find the money comes from one place and the losses from another — which is the fastest way to find the biggest leak and cut it.
You need a record of your trades and about ten minutes. The point is not the arithmetic, it is what you do with the number once you have it.
One row per trade: entry, exit, the amount you risked, and the outcome as a multiple of that risk. Winners as +R, losers as −R, costs included. Without this record there is no expectancy to calculate, which is why the journal comes before the number, not after it.
Take your win rate, your average win, and your average loss across a few hundred trades and drop them into (Win rate × Average win) − (Loss rate × Average loss). That is your expectancy per trade. Positive means the strategy makes money; negative means it costs you money, no matter how the last week felt.
Recalculate per setup, per session, per instrument. You are looking for the pockets of strong positive expectancy to do more of, and the negative ones to cut. Most traders discover their edge is concentrated in a couple of setups and everything else is treading water — the same pattern that shows up across your core performance metrics.
A positive expectancy is fragile. Oversizing after a hot streak, revenge-sizing after a loss, drifting into lower-quality trades, or slippage creeping up all eat the edge from the inside. Once you know your number, most of the job is defending it — sizing consistently, sticking to the setups that carry it, and not manufacturing trades your rules never asked for. Raising the number itself usually means a better win rate or a better payoff, not more volume.
Our free Excel journal auto-calculates win rate, average win and loss, profit factor and expectancy from one row per trade — the same numbers this post is built on, in a sheet you already know how to use.
Get the free templateThe bottom line: win rate is the number you feel, expectancy is the number you get paid on. Blend your win rate with your average win and average loss into a single figure, measure it in R so it travels, calculate it over a real sample with costs included, and split it to see where the edge actually lives. Do that and you stop arguing with yourself about whether the strategy works — the number already told you, and the only job left is to trade it enough and not leak it away.
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Tracker Fx Team