Expectancy

Updated 2026-09-20

Definition

The average gain per trade, usually measured in R: win percentage times average R won, minus loss percentage times average R lost.

Why it matters

A system is only interesting if it has positive expectancy over a large sample, with costs included. It's an average: in the short run long losing streaks can occur.

Practical example

40% wins at +2.5R and 60% losses at −1R: 0.4 × 2.5 − 0.6 × 1 = +0.4R per trade.

Learn more

Course lesson: Risk/reward and expectancy: the maths that tells you whether a system works

Related entries

Want to compare notes with other traders?

Join the community to share ideas and questions, or the free signal room on Telegram.

Full glossary

Educational content, not financial advice. Trading involves risk.