Traders like to quote their win rate. It is easy to understand and satisfying when high. But win rate on its own says almost nothing about whether an approach makes money.
What matters is the combination of how often you win and how much you win or lose each time. This article explains the risk-reward ratio, expectancy, and the practical traps in measuring both.
Two numbers that only mean something together
Win rate is the share of trades that make money.
Risk-reward ratio compares the typical size of a win with the typical size of a loss. If the average win is 3,000 and the average loss is 1,000, the ratio is 1:3 — you risk one to make three. If the average win is 1,000 and the average loss is 3,000, it is the reverse.
Neither number tells you anything alone. A 90 percent win rate is a disaster if each loss wipes out twenty wins. A 30 percent win rate is excellent if each win is five times the size of each loss.
There is also a natural tension between them. Approaches that aim for large wins — buying options, trend-following — tend to win less often. Approaches that take small, frequent profits — selling options, quick scalps — tend to win often but suffer occasional large losses. Neither style is better. What matters is whether the combination is profitable.
Expectancy: the number that combines them
Expectancy is the average amount made or lost per trade:
Expectancy = (win rate × average win) − (loss rate × average loss)
Example A: win rate 70 percent, average win 1,000, average loss 3,000.
0.70 × 1,000 = 700. 0.30 × 3,000 = 900. Expectancy = −200 per trade.
Example B: win rate 35 percent, average win 3,000, average loss 1,000.
0.35 × 3,000 = 1,050. 0.65 × 1,000 = 650. Expectancy = +400 per trade.
Example A wins twice as often and loses money. Example B loses most of the time and makes money.
From the same formula, you can work out the minimum win rate needed to break even for any risk-reward ratio:
With wins equal to losses (1:1), you need to win more than 50 percent.
With wins twice the size of losses (1:2), you need more than about 33 percent.
With wins one-third the size of losses (3:1 against you), you need more than 75 percent.
This is the most useful single check on any approach. Compare the win rate it actually achieves with the break-even win rate its risk-reward ratio requires.
Costs change the answer
Expectancy should always be calculated after costs — brokerage, exchange charges, taxes and the bid-ask spread on entry and exit.
Costs hit approaches with small average wins hardest. If the average win is 500 and round-trip costs are 100, a fifth of every win disappears before anything else is considered. An approach that looks slightly profitable before costs can be clearly unprofitable after them.
This is particularly relevant in options, where frequent trading of low-priced contracts can make charges and spreads a large share of each result. Always use net figures from your broker's profit and loss report, not your own estimate of gross results.
Taxes on trading income also reduce what you keep. They do not change whether an approach has an edge, but they affect whether the edge is worth the time and risk involved.
Sample size, and streaks
Expectancy calculated from ten trades is almost meaningless. Results over a small number of trades are dominated by luck. A few dozen trades give a rough indication; something closer to a hundred gives a more reliable picture, and even then the market conditions during those trades matter.
Streaks are larger than intuition suggests. With a win rate of 40 percent, a run of seven or eight consecutive losses somewhere in a hundred trades is quite likely, even if the approach is profitable overall. Traders who do not expect this abandon good approaches during an ordinary losing streak.
The reverse also happens. An approach with negative expectancy can produce a long winning streak, especially one based on selling options, where the large loss arrives rarely. A few months of success is not proof of an edge.
Two practical rules follow. First, size positions so that a long losing streak is survivable — the streak will come. Second, judge an approach on a meaningful sample and on its worst loss, not only on its recent run.
Using this on your own trading
Keep a journal with net results per trade. Download trade-level reports from your broker to avoid errors.
Calculate monthly: win rate, average win, average loss, expectancy after costs, and the largest single loss.
Separate by approach. If you buy options on some trades and sell spreads on others, calculate each separately. A profitable approach can hide a losing one.
Compare with the break-even win rate. If your actual win rate is below what your risk-reward ratio requires, the approach is losing money on average, however it feels.
Watch the tail. If the largest loss is many times the average win, cap it with defined-risk structures or hard limits before it recurs.
Stop negative lines. If an approach has negative expectancy after costs over a meaningful sample, stop it, regardless of how often it wins.
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This is educational material, not advice, and nothing here recommends any position or approach. We run no tips group and no signal service, we manage nobody's money, and no return is promised. Derivatives can lose more than the amount blocked against them.
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Frequently Asked Questions
What is a good win rate in trading?
There is no good win rate on its own. It depends on the risk-reward ratio. A 35 percent win rate can be very profitable with large wins, and an 80 percent win rate can lose money with large losses.
What is the risk-reward ratio?
A comparison of the average size of wins with the average size of losses. Risking 1,000 to make 3,000 on average is a 1:3 ratio.
How do I calculate expectancy?
Multiply the win rate by the average win, multiply the loss rate by the average loss, and subtract the second from the first. Use net figures after all costs.
What win rate do I need to break even?
It depends on the ratio. With equal wins and losses you need above 50 percent; with wins twice the size of losses, above about 33 percent; with losses three times the size of wins, above 75 percent.
How many trades do I need to judge a strategy?
Ten is almost meaningless. A few dozen gives a rough indication, and closer to a hundred is more reliable. Expect losing streaks along the way even in a profitable approach.
Related Reading
- The options course, for Ludhiana
- A high-win-rate structure, examined
- What losing streaks do to decisions
- The costs that reduce every result
- When a negative run is real
- Sizing to survive a streak
Disclaimer: TheFinBaba provides educational content only - this is not investment advice. Trading involves risk of loss.
