Bankroll Simulator

Last updated: 2026-07-14

Monte Carlo bankroll simulation for prediction market traders and sports bettors. Simulate hundreds of betting paths to estimate probability of ruin, expected growth, and drawdown risk.

Median outcome
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Set your budget, your advantage, and bet size to see how your bankroll is likely to move.

Bankroll Paths

Median
5th/95th percentile
Starting Budget

Why Simulate Bankroll Outcomes Before Betting?

A positive edge does not guarantee profits over any finite sequence of bets. Variance can wipe out an undercapitalized bettor even with a genuine 5% edge. This simulator shows the full distribution of possible outcomes so you can calibrate bet sizing to match your risk tolerance. Professional bettors and prediction market traders use simulations like this to stress-test their strategies before risking real capital.

How Does Comparison Mode Help?

Comparison mode runs two different strategies with the exact same random sequence. This isolates the effect of your strategy change. For example, compare 2% Kelly sizing against flat $100 bets: same edge, same odds, same luck sequence, different outcomes. The chart overlays both strategies so you can see where they diverge. Use the Kelly Calculator to find optimal percentage sizing, then simulate it here.

What Bankroll Strategy Do Professional Traders Use?

Most professional bettors use fractional Kelly sizing, typically between one-quarter and one-half Kelly. Full Kelly maximizes long-run growth rate but produces severe drawdowns. Half Kelly sacrifices about 25% of the growth rate while cutting drawdown risk roughly in half. Use this simulator to find the sizing that matches your tolerance: set the edge and odds for your typical trade, then adjust bet size percentage until the average max drawdown falls below your comfort threshold. Our live dashboard helps you identify markets where your edge is highest.

Frequently Asked Questions

What is a Monte Carlo bankroll simulation?
A Monte Carlo simulation generates hundreds or thousands of random betting outcomes based on your edge, odds, and bet sizing strategy. Each "path" shows one possible future for your bankroll. By analyzing many paths together, you get a statistical picture of likely outcomes, worst cases, and probability of going broke.
What does probability of ruin mean?
Probability of ruin is the percentage of simulated paths where your bankroll hit the ruin threshold (typically $0). A 5% ruin probability means that in 5 out of 100 simulations, your bankroll dropped to zero. Lower is better. Even with a positive edge, aggressive bet sizing can produce high ruin probability.
What is the difference between fixed and percentage bet sizing?
Fixed betting risks the same dollar amount on every bet regardless of bankroll size. Percentage betting (like Kelly criterion) risks a fixed percentage of your current bankroll. Fixed betting can lead to ruin if you hit a losing streak. Percentage betting can never reach exactly zero, but can suffer severe drawdowns.
How does edge affect simulation results?
Edge is the percentage by which your true win probability exceeds the implied probability from the odds. A 5% edge at 2.00 decimal odds means you win 55% of the time instead of the implied 50%. Higher edge produces faster bankroll growth but does not eliminate variance risk on any individual sequence of bets.
What does the random seed control?
The seed determines the specific sequence of random numbers used. Same seed produces identical results every time, making comparisons fair. In comparison mode, both strategies use the same seed, so differences in outcomes are entirely due to the strategy parameters, not randomness.
How should I interpret the P5 and P95 lines?
P5 represents the 5th percentile outcome — only 5% of paths end with a lower bankroll. P95 represents the 95th percentile — only 5% of paths end higher. The range between P5 and P95 covers 90% of likely outcomes. A wider gap means higher variance in your strategy.
What is average maximum drawdown?
Maximum drawdown is the largest peak-to-trough decline in a single path, expressed as a percentage. Average max drawdown is the mean of this value across all simulated paths. A 30% average max drawdown means you should expect your bankroll to drop about 30% from its peak at some point during the betting sequence.
How many paths should I simulate?
For quick estimates, 100-200 paths are sufficient. For more precise statistics (especially ruin probability), use 500-1000 paths. The simulation runs in a Web Worker so it will not freeze your browser. More paths produce smoother charts and more reliable percentile estimates.

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