Published
Every trading course sells you the same dream: get your win rate up and the money takes care of itself. A 60% win rate sounds like a license to print. So we tested it — properly, with 40,000 simulated accounts each trading 300 times — and the result is uncomfortable. A 60% win rate can still blow you up almost half the time. It depends on one number the courses barely mention: how much you risk per trade.
The experiment
We took a genuinely winning trader: 60% win rate, wins and losses the same size (1:1). That's a real edge — over 300 trades you expect to be up nicely. Then we ran 40,000 fresh accounts through random trade sequences with exactly that edge, sizing every trade as a fixed percent of the account, and counted how many fell to half their starting balance (our definition of "ruined"). Only the risk-per-trade changed.
60% win rate, 1:1, chance of losing half your account within 300 trades:
- Risk 1% per trade → 0.0% ruin
- Risk 2% per trade → 0.0%
- Risk 5% per trade → 0.7%
- Risk 10% per trade → 10.5%
- Risk 20% per trade → 45.1%
- Risk 30% per trade → 74.5%
Same trader. Same edge. Same 40,000 simulations. At 2% per trade the account is essentially bulletproof. At 20% — a size plenty of people use without blinking — that winning trader has a 45% chance of blowing up half the account. Almost a coin flip, with a real edge, purely from betting too big.
Win rate is the weakest lever
Here's the part that stings. Improving your strategy helps far less than fixing your sizing. Take a stronger setup — 55% win rate but 2:1 reward to risk (a bigger edge than the first trader):
- Risk 5% per trade → 0.0% ruin
- Risk 10% per trade → 1.7%
- Risk 20% per trade → 15.4%
Better edge, and 20% sizing still hands you a 1-in-6 chance of ruin. Meanwhile the weaker trader who simply drops to 2% risk sits at zero. You can out-size a good strategy into the ground, and you can rescue a mediocre one with discipline. Position size dominates.
And if you have no edge, nothing saves you
To be fair to the math: sizing isn't magic. Run a losing trader — 40% win rate at 1:1, a negative edge — and the picture is grim at any size:
- Risk 2% per trade → 96.9% ruin
- Risk 5% per trade → 100%
Small sizing buys a losing strategy time, not survival. The order of operations is clear: first make sure you actually have an edge, then protect it with sizing. Tiny bets on a bad system just lose slowly.
What to actually do
Stop obsessing over win rate and start respecting size. For most people the honest answer is 1–2% of the account per trade — boring, and the single biggest reason some accounts survive a rough streak while others vanish. Decide that number before the trade with the position size calculator, sanity-check a single trade with the Rekt Risk Score, and run your own win rate and reward:risk through the risk of ruin calculator to see your real blow-up odds. Remember too that deep drawdowns are brutal to recover from — down 50% needs +100% just to get even, which is exactly why "ruin" at half your account is the line that matters.
A 60% win rate is great. It's just not a seatbelt. The seatbelt is the size of your bet.
Method: 40,000 Monte Carlo accounts, 300 trades each, fixed-fractional sizing, "ruin" = balance falls to 50% of start. Simulated, not a guarantee — but the relationship between size and ruin is robust.