Win/Loss Ratio vs. Expectancy: Why Your 80% Win Rate Won’t Save You from Being Skint

Let me tell you a story.

Back in 2015, I knew a lad—proper City boy type, sharp suit, sharper jawline. He’d marched into the forex game with what he called his “golden system.” He’d backtested it to death. Eighty percent win rate. EIGHTY. He walked around the office like he’d cracked the code, talking about how he’d finally beaten the market. Six months later, he was working at his dad’s insurance firm in Surrey.

His win/loss ratio looked pristine on paper. His account? Looked like a decimal point had gone missing.

This is the story of why 90% of retail traders focus on the entirely wrong metric, and why I’m about to save you approximately £50,000 and your dignity.

The Problem: Traders Fall in Love with Win Rate Like It’s a Supermodel

Here’s the thing about win/loss ratio that nobody wants to hear: it’s almost completely irrelevant to whether you make money.

I know. Counterintuitive. Shocking. You’ve probably built your entire trading journal around it.

The human brain is a pattern-recognition machine that’s desperately in love with the idea of being right. Winning feels good. Winning 80 times out of 100 feels incredible. Your ego swells. You tell your mates down the pub about your “hit rate.” You imagine yourself in a penthouse overlooking the Thames.

Then you check your account balance and it’s down 40%.

How is this possible? How can you win so much and still lose money?

The answer is hideously simple: size matters far more than frequency.

If you win £100 on 80 trades and lose £1,000 on 20 trades, congratulations—you’ve made £8,000 gross and lost £20,000. Your win rate is 80%. Your net result is getting absolutely mullered.

Your 80% win rate has driven you into a hole while making you feel successful. It’s the financial equivalent of being in a terrible relationship where the other person occasionally texts you back.

Enter Expectancy: The Metric That Actually Predicts Your Retirement Plans

Mathematical expectancy is what separates the profitable traders from the broke ones who are suspiciously active on TikTok sharing “trading tips.”

Mathematical Expectancy = (Win% × Average Win) - (Loss% × Average Loss)

This is the number that matters. This is your actual edge. This is whether you’re drinking champagne at Nobu or ramen at home contemplating whether you should’ve become an accountant.

Let me work through an example that’ll make this clearer than a morning after a light night out.

Trader A:

• Win Rate: 80%
• Average Win: £100
• Average Loss: £500
• 100 trades

Expectancy = (0.80 × £100) - (0.20 × £500) Expectancy = £80 - £100 Expectancy = -£20 per trade

Over 100 trades, Trader A loses £2,000. Despite winning 80 times.

Trader B:

• Win Rate: 40%
• Average Win: £500
• Average Loss: £200
• 100 trades

Expectancy = (0.40 × £500) - (0.60 × £200) Expectancy = £200 - £120 Expectancy = +£80 per trade

Over 100 trades, Trader B makes £8,000. Despite losing 60 times.

If you sat these two traders next to each other, your brain would tell you Trader A is obviously better. Your math tells you Trader B is absolutely cleaning up while Trader A is quietly going bankrupt.

This is why I can’t stand watching retail traders obsess over win percentage like it’s their kid’s exam results. It’s the wrong test entirely.

The Psychological Minefield

Here’s where it gets properly interesting—and genuinely dangerous.

A high win rate is psychologically addictive. Each win reinforces the narrative in your head: “I’m good at this. I’m beating the market. I’m a winner.” Your dopamine receptors are having a field day. You’re confident. Maybe overconfident.

Then—because mathematics is unforgiving—you take one of those necessary losses. Except now you’ve got 79 wins in your back pocket, so you double down to “get it back.” You’re not thinking clearly because your brain is clouded with the memory of all that winning.

Next thing you know, that one loss has become three losses, and suddenly you’re not winning anymore, and the psychological collapse is catastrophic.

I’ve seen traders with 75% win rates blow entire accounts in three weeks because they couldn’t handle the inevitable downswing. Meanwhile, traders with 45% win rates keep the lights on because they’ve built their systems around positive expectancy, not ego gratification.

The Brutal Truth About Your Strategy

If your strategy has a positive expectancy and negative win rate, you’re potentially sitting on a goldmine. It means you’re letting your winners run and cutting losers quickly—the most fundamental principle of profitable trading.

If your strategy has a high win rate and negative expectancy, you’re a lottery ticket with legs. You might make money for three months. You’ll probably go broke in six.

The market doesn’t care about your feelings or your percentage of correct predictions. It cares about your bottom line.

What You Actually Need to Do

Stop looking at your win rate. Seriously. Delete it from your trading journal.

Start calculating your expectancy for every strategy you trade. Every single one. It’s boring math, but it’s the difference between a career and a cautionary tale.

Run a proper backtest on 100+ trades. Calculate that expectancy number. Is it positive? How positive? If you’re making £5 per trade on average, how many trades can you reasonably execute before variance grinds you into dust?

Then—and this is the crucial bit—only trade strategies with genuinely positive expectancy. Not probably positive. Not “I think it will be.” Actually positive, confirmed through backtesting.

Your win rate can be 30%. Your expectancy can be +£150 per trade. You’ll be wealthy.

Your win rate can be 90%. Your expectancy can be -£50 per trade. You’ll be back in Surrey working for your dad.

Final Thought

I’ve made more money with a 35% win rate than most traders will in a lifetime with their 75% win rates. I’ve also watched traders with 85% win rates lose everything in six months.

The market’s not interested in your hit rate. It’s interested in your expectancy. And until retail traders figure that out, I’ll keep seeing the same story play out over and over again: sharp suits, golden systems, and accounts heading straight downhill.

Don’t be that trader. Focus on expectancy. Your future self will thank you.

Now, stop reading blog posts and go calculate your actual edge.