Expectancy tells you the average profit or loss per trade, in R. A positive expectancy (>+0.10R per trade) means your strategy is profitable. Most traders chase win rate (wrong) instead of expectancy (right). A strategy with 30% win rate and 3:1 payoff has higher expectancy than a 60% win rate strategy with 0.8:1 payoff.
- Expectancy is the only metric that predicts profitability
- Calculate expectancy before you start trading (from your past data or backtests)
- Expectancy > +0.10R per trade = profitable over time
- Variance means you can lose money despite positive expectancy for 10–20 trades
Expectancy is the magic formula. Once you understand it, you stop optimizing for the wrong things.
The formula
Expectancy = (Win rate × Avg win) − (Loss rate × Avg loss)
All values in R.
Walking through an example
Your data (50 trades):
- 18 wins: +$1,200 = 18 × avg win → avg win = $67
- 32 losses: −$800 = 32 × avg loss → avg loss = $25
- Risk per trade: $50
Calculate in R:
- Avg win: $67 ÷ $50 risk = +1.34R
- Avg loss: $25 ÷ $50 risk = −0.50R
- Win rate: 18 ÷ 50 = 36%
- Loss rate: 32 ÷ 50 = 64%
Expectancy:
- Expectancy = (36% × 1.34R) − (64% × 0.50R)
- Expectancy = 0.4824R − 0.32R
- Expectancy = +0.1624R per trade
What it means: On average, each trade nets you +0.1624R (or +$8.12 per trade on $50 risk).
Over 100 trades: 100 × $8.12 = +$812 expected profit.
Know Your Real Risk on Every Trade
TRADZY tracks R-multiples, drawdown and daily loss automatically, so your rules hold when it matters.
Track Risk in TRADZY →Interpreting expectancy
| Expectancy | Interpretation |
|---|---|
| < 0 | Negative expectancy; losing strategy |
| 0 to +0.05R | Barely profitable; high variance kills it |
| +0.05 to +0.15R | Profitable, but weak edge |
| +0.15 to +0.30R | Solid edge |
| +0.30 to +0.50R | Strong edge |
| > +0.50R | Excellent edge (usually small sample) |
Why expectancy beats win rate
Trader A: 60% win rate
- Win rate: 60%
- Loss rate: 40%
- Avg win: +0.5R
- Avg loss: −1.0R
- Expectancy = (60% × 0.5R) − (40% × 1.0R) = 0.30R − 0.40R = −0.10R (LOSING)
Trader B: 35% win rate
- Win rate: 35%
- Loss rate: 65%
- Avg win: +2.5R
- Avg loss: −1.0R
- Expectancy = (35% × 2.5R) − (65% × 1.0R) = 0.875R − 0.65R = +0.225R (WINNING)
Trader B has 25 percentage points lower win rate but 25× higher expectancy.
Lesson: Optimize for payoff ratio and win rate together, not win rate alone.
Calculating expectancy from your journal
After 50+ trades in your trading journal:
- Add up all R from wins: +1.2R, +0.8R, +2.1R, +0.5R, +1.5R, +0.9R, +2.2R, +1.1R, +0.7R, +1.8R = +13.8R total
- Divide by # of wins: 13.8R ÷ 10 wins = +1.38R average win
- Add up all R from losses: −1.0R, −1.0R, −0.8R, −1.2R, −0.9R = −5.0R total
- Divide by # of losses: 5.0R ÷ 5 losses = −1.0R average loss
- Calculate win rate: 10 wins ÷ 15 total = 66.7%
- Calculate loss rate: 5 losses ÷ 15 total = 33.3%
- Plug into formula:
Expectancy = (66.7% × 1.38R) − (33.3% × 1.0R) = 0.92R − 0.33R = +0.59R per trade
This is a strong edge.
Expectancy by setup
Calculate it for each setup:
| Setup | Trades | Avg win | Avg loss | Win rate | Expectancy |
|---|---|---|---|---|---|
| ORB | 25 | +1.5R | −1.0R | 52% | +0.28R ✅ |
| VWAP | 18 | +1.2R | −1.0R | 44% | +0.13R ⚠️ |
| Gap | 12 | +0.8R | −1.1R | 42% | −0.10R ❌ |
Action:
- Trade more ORBs (strong expectancy)
- Consider cutting gap fades (negative expectancy)
- Test VWAP with better entry/exit rules (weak but positive)
The variance problem
Positive expectancy doesn't guarantee short-term profits.
Example:
- Your strategy has +0.2R expectancy
- 10-trade sample: +2R expected
- Actual result: −1.5R (you got unlucky)
This is normal. Variance is real.
What to do:
- Never judge your strategy on <30 trades
- Track expectancy from your past data, not every 10 trades
- Run 100+ trades before deciding the system is broken
Expectancy and sample size
Small sample = big variance.
| Sample size | Can you trust it? |
|---|---|
| 10 trades | No. Could be luck. |
| 30 trades | Maybe. Directional signal. |
| 50 trades | Probably. Getting reliable. |
| 100+ trades | Yes. Fairly reliable. |
If you calculate +0.2R expectancy from 10 trades, you got lucky. If you calculate it from 100 trades, it's real.
Expectancy and position sizing
Expectancy scales with position size.
- Expectancy per trade: +0.2R = +$200 on $50 risk
- Scale: 10 trades per day × +$200 = +$2,000 per day
But this is theoretical. Variance means:
- Some days: +$5,000
- Some days: −$1,500
- Average: +$2,000
You need enough capital to survive bad weeks.
Negative expectancy (and what to do)
If your expectancy is negative:
- Wrong strategy? Test on paper trading first. If it's still negative, move on.
- Wrong implementation? You know what works but can't execute it. Add rules/checklist.
- Sample bias? Only 20 trades. Run 50 more and recalculate.
If negative after 100 trades: Stop. Find a new strategy.
There's no shame in cutting losses on a strategy that doesn't work.
FAQ
How do I calculate expectancy if I haven't traded yet?
Use historical data or backtests. Run your setup on the past 100 trades and calculate expectancy.
Should I adjust expectancy for commission?
Yes. If you pay $5 commission per trade and your expectancy is +$6, real expectancy is +$1 after costs. This is why low-commission brokers matter.
Can I have high expectancy but still lose money?
Yes, short-term. Variance is real. But over 300+ trades, positive expectancy compounds.
What if expectancy is +0.05R (barely profitable)?
It's profitable, but fragile. One small thing breaks (commission increase, slippage increase, emotional trading) and you're negative. Target: +0.15R or higher for a real edge you can scale.
How often should I recalculate expectancy?
After every 50 new trades. Markets change, your setup might shift.
Is expectancy the same as ROI?
No. ROI is return on investment (profit ÷ account size). Expectancy is expected profit per trade. Related but different. Expectancy is more useful for traders because it's independent of account size.
Put This Into Practice
- Set your risk per trade and daily loss limit once
- Track every trade in R, not dollars
- Watch drawdown and expectancy update automatically
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Educational content, not financial advice. Trading involves substantial risk of loss.