Master the math behind consistent trading. Learn how win rate, risk-reward ratio, and expected value work together — and why a 40% win rate can make you more money than 70%.
Win rate is the percentage of your trades that are profitable. The formula is simple:
Win Rate = (Winning Trades / Total Trades) × 100
If you take 100 trades and 45 are profitable, your win rate is 45%. Simple enough — but here's where most traders go wrong: they assume a higher win rate automatically means more profit.
A trader with a 75% win rate who averages $50 per win and $200 per loss will lose money over time. Winning often doesn't help if your losses are large.
A trader with a 35% win rate who averages $400 per win and $100 per loss is highly profitable. Winning big when you're right compensates for frequent small losses.
The risk/reward ratio (R/R) measures how much you stand to gain relative to how much you're risking on a trade. It's calculated from your entry price, stop-loss, and take-profit:
R/R = (Take Profit − Entry) / (Entry − Stop Loss) [for longs]
A 1:2 R/R means you risk $1 to potentially gain $2. Below is the break-even win rate for each R/R — the minimum win rate needed to avoid losing money:
| Risk/Reward | Break-Even Win Rate | Interpretation |
|---|---|---|
| 1:1 | 50.0% | Must win more than half — no margin for error |
| 1:1.5 | 40.0% | Losing majority of trades is fine |
| 1:2 | 33.3% | One winner pays for two losers |
| 1:3 | 25.0% | One winner pays for three losers |
| 1:4 | 20.0% | One winner pays for four losers |
| 1:5 | 16.7% | One winner pays for five losers |
The tradeoff: higher R/R ratios require wider take-profit targets, which means trades take longer and hit TP less often. There's no free lunch — you trade win rate for reward size.
Expected value (EV) is the single number that tells you whether a trading strategy makes money. It combines win rate and average win/loss into a per-trade expectation:
EV = (Win% × Average Win) − (Loss% × Average Loss)
Win rate: 70%, Avg win: $80, Avg loss: $200. EV = (0.70 × $80) − (0.30 × $200) = $56 − $60 = −$4 per trade. Losing money despite winning 7 out of 10 trades.
Win rate: 35%, Avg win: $400, Avg loss: $100. EV = (0.35 × $400) − (0.65 × $100) = $140 − $65 = +$75 per trade. Highly profitable despite losing most trades.
Win rate: 55%, Avg win: $120, Avg loss: $160. EV = (0.55 × $120) − (0.45 × $160) = $66 − $72 = −$6 per trade. Looks decent on the surface but bleeds money slowly.
Even a strategy with strong positive EV will have losing streaks. This is variance — the natural randomness in outcomes. The problem: with a small sample size, variance can completely mask your edge.
| Win Rate | Consecutive Losses | Probability |
|---|---|---|
| 50% | 5 in a row | 3.1% |
| 50% | 7 in a row | 0.8% |
| 50% | 10 in a row | 0.1% |
| 40% | 5 in a row | 7.8% |
| 40% | 7 in a row | 2.8% |
| 40% | 10 in a row | 0.6% |
At a 50% win rate, a streak of 5 consecutive losses has a 3.1% chance of occurring — meaning in every 100-trade sample, you should expect it to happen. At a 40% win rate, losing streaks are even more common. This is normal, not a sign your strategy is broken.
Trade your edge on Dexly
The most profitable traders are rarely the cleverest. They're the most consistent. They find an edge, define their process, and execute it without deviation — trade after trade, week after week.
Judges every trade by its result. Changes strategy after a losing streak. Increases size after wins, decreases after losses. Chases new setups and indicators. Emotional rollercoaster tied to P&L.
Judges trades by whether they followed the plan. Sticks with a strategy through variance. Consistent position sizing regardless of recent results. Trusts the edge over a large sample. Emotionally detached from individual outcomes.
Process-focused trading is boring. That's the point. Excitement in trading usually means you're doing something wrong — oversized positions, impulsive entries, or trades outside your plan. For more on building the right mindset, read Trading Psychology. For the full roadmap to consistency, see How to Become a Profitable Trader.
Before risking real money on a strategy, test it against historical data. Backtesting gives you a statistical sample without financial risk.
Write down exact entry and exit criteria. If you can't describe them unambiguously in writing, they're not rules — they're vibes.
Go through past charts and identify every trade your rules would have triggered. Be honest — don't skip trades that look bad in hindsight.
Record entry, exit, TP, SL, and result for each trade. Calculate win rate, average win, average loss, and expected value.
After backtesting shows positive EV, run the strategy in real-time on a paper account for at least 50 trades. This catches issues that backtesting misses — like execution difficulty and psychological challenges.
All of these concepts translate directly to trading on Dexly. Here's how to put the math into practice:
For a complete guide to position sizing and TP/SL placement, see Position Sizing & Risk Management.
Perps, spot, copy & prediction markets in one fast, non-custodial app. Get Dexly on iOS & Android and start in seconds.
Risk Warning: Trading perpetual futures involves significant risk of loss. Only trade with capital you can afford to lose. Dexly is a non-custodial interface; you are responsible for your own funds and trading decisions.
Trade your edge on Dexly
