Scenarios: 2% stake, 200 trades, $1,000 start
| Win rate | Payout | Expected result per $100 staked | Median final balance | 10th–90th percentile | Down 50% or more |
|---|---|---|---|---|---|
| 50% | 80% | −$10.00 | $649 | $452 – $897 | 14.3% |
| 50% | 85% | −$7.50 | $716 | $494 – $999 | 10.1% |
| 50% | 90% | −$5.00 | $790 | $540 – $1,112 | 4.4% |
| 55% | 80% | −$1.00 | $930 | $672 – $1,287 | 0.7% |
| 55% | 85% | +$1.75 | $1,037 | $743 – $1,447 | 0.4% |
| 55% | 90% | +$4.50 | $1,155 | $820 – $1,627 | 0.2% |
| 60% | 80% | +$8.00 | $1,335 | $965 – $1,781 | 0.0% |
| 60% | 85% | +$11.00 | $1,502 | $1,076 – $2,020 | 0.0% |
| 60% | 90% | +$14.00 | $1,690 | $1,200 – $2,291 | 0.0% |
Each row: 1,000 simulated runs with seed 42. Simulations show a range of outcomes; they are not a forecast.
FAQ
Why is the median balance lower than the expected balance?
With a percentage stake, a loss shrinks the base for the next trade more than a win grows it. At a 55% win rate, 85% payout and 2% stake, the expected balance after 200 trades from $1,000 is about $1,072, but the median run ends near $1,037.
What happens at a 50% win rate with an 85% payout?
Each trade loses 7.5% of the stake on average. With a 2% stake, the median run falls from $1,000 to about $716 over 200 trades, and close to 1 in 10 runs ends with half the balance or less.
Is a fixed stake or a percentage of balance safer?
A percentage stake shrinks after losses. At a 50% win rate and 85% payout over 200 trades, a fixed $20 stake on $1,000 ends down 50% or more in about 22% of runs; a 2% stake does so in about 9%.