Expectancy in Trading
Expectancy is the average amount of profit or loss you expect per trade based on historical performance. It combines your win rate, average winning trade size, and average losing trade size.
In depth
Expectancy is a mathematical concept that reveals whether your trading system is profitable. It answers a simple question: on average, how much do I make or lose per trade? The calculation uses three variables: your win percentage, your average win size, and your average loss size.
The formula is straightforward: (Win % × Average Win) - (Loss % × Average Loss). For example, if you win 55% of trades with an average gain of $500, and lose 45% with an average loss of $400, your expectancy equals (0.55 × $500) - (0.45 × $400) = $275 - $180 = $95 per trade.
Expectancy becomes powerful over time. A small positive expectancy of $20 per trade generates $400 in profits after 20 trades. After 100 trades, that becomes $2,000. This is why consistency matters more than home runs. A system with +$50 expectancy outperforms a system with wild swings and zero expectancy over hundreds of trades.
Negative expectancy is the silent killer of trading accounts. Even a skilled trader loses money long-term with -$30 expectancy per trade. Most retail traders operate with negative expectancy and never realize it because they don't track their trades properly. This is where discipline and data collection become crucial.
Why it matters
Your expectancy determines your financial future as a trader. Positive expectancy means compounding wealth. Negative expectancy means slow account death. Understanding your actual expectancy separates profitable traders from those losing money.
Expectancy also reveals whether you should take a trade at all. If your edge generates only +$15 per trade but requires $500 in risk, skip it. Find trades where expectancy justifies the risk and time commitment. Many traders chase low-expectancy setups because they seem exciting, not because they make money.
Without knowing your expectancy, you're flying blind. You might think you're profitable when you're actually slowly losing money. Or you might abandon a winning system during a drawdown. Expectancy gives you objective truth.
TraderLog automatically calculates your expectancy as you log trades. You see your true win rate, average wins, and average losses in real time. This removes guesswork from evaluating your trading system.
Our platform tracks expectancy across different strategies, timeframes, and asset classes. You can compare which trading methods actually generate positive expectancy. You identify your best edge and double down on it. You spot negative-expectancy patterns and eliminate them before they drain your account.
TraderLog's dashboard shows expectancy trends over time. You watch as your consistency improves. This data-driven feedback loop accelerates your journey to profitability.
Frequently asked questions
Yes, in the short term. Positive expectancy guarantees long-term profits only across a large sample size. Bad luck or variance can create losing streaks. Trade 10 times, you might lose. Trade 1,000 times with positive expectancy, and probability strongly favors profit.
At least 30 trades per system, ideally 100 or more. With fewer trades, variance dominates and expectancy becomes unreliable. The larger your sample size, the more confident you can be in the number.
It depends on your risk per trade. If you risk $100 per trade, +$50 expectancy is excellent. If you risk $1,000, +$50 is weak. Compare expectancy to your risk to evaluate true return on risk.
Track Expectancy in Trading in your trading journal.
TraderLog calculates Expectancy in Trading automatically across your trade history, and shows you exactly when and why it changes.