RISK MANAGEMENT
Monte Carlo Simulator
One backtest shows you a single roll of the dice. This simulator rolls your stats 1,000 times — same win rate, same average win and loss, different luck — and shows the full range of equity curves your edge can produce.
100% free · no signup · nothing leaves your browser
MONTE CARLO SIMULATOR
Live1,000 runs · same inputs, same result — reproducible by seed
MEDIAN FINAL BALANCE
$30,000.00
+20% vs start
5TH PERCENTILE (P5)
$22,000.00
1 in 20 runs ended at or below this
95TH PERCENTILE (P95)
$38,000.00
1 in 20 runs ended at or above this
Fixed-dollar risk model: every trade adds +avg win or −avg loss — no compounding, no sizing changes. Assumes independent trades and a constant win rate. A stress test of your stats, not a prediction.
each trade: balance += (rand < win rate) ? +avg win : −avg loss · 1,000 runs · seeded PRNG (reproducible)THE MATH
Why a single equity curve lies to you
Your win rate and average win/loss define an edge — but they don't define an outcome. The same edge produces wildly different curves depending purely on the order the wins and losses arrive.
A 45% win rate with $600 average wins against $400 average losses is a genuinely positive edge: about +$50 of expectancy per trade. But over 100 trades, luck decides whether the winners cluster early or the losers do. One sequencing of those exact stats produces a smooth climb; another produces a 15-trade losing stretch that would convince most traders their strategy is broken. A single backtest — or a single good month — shows you exactly one of those sequences and tempts you to treat it as the truth.
Monte Carlo simulation fixes this by brute force: it replays your stats a thousand times with different random orderings and reports the distribution instead of an anecdote. The question changes from “what happened?” to “what does this edge typically do, and how bad does it get when it’s unlucky?” That second question is the one that determines whether you survive long enough for the edge to pay.
READING THE OUTPUT
How to read the fan — and why p5 is the number that matters
The bright line is the median path. The band holds 90% of simulated outcomes. The faint paths are individual runs — each one a possible version of your next 100 trades.
The median final balance tells you what this edge typically delivers. The p95 is the run you’ll remember and screenshot; the p5 is the run you have to be able to survive. If the p5 outcome — the result one unlucky trader in twenty gets from your exact stats — would make you abandon the strategy, cut your size, or blow a risk limit, then your position sizing is wrong for your edge, even though the edge is real.
The drawdown rows matter just as much as the finals. The median max drawdown is what a normal run of this strategy feels like at its worst moment; the worst-path drawdown shows what pure bad luck can do with no change in your edge at all. Traders who haven’t seen those numbers routinely quit profitable systems in the middle of an ordinary drawdown. If you want to test the strategy itself — not just its luck — run it against historical data in the TerraTrade backtester and feed the resulting stats back in here.
FAQ
What does a Monte Carlo simulation tell a trader?+
It reshuffles the order of wins and losses your stats imply, 1,000 times, to show the range of equity curves the same edge can produce. Instead of one backtest curve, you see the spread of realistic outcomes — including how deep the drawdowns can get purely from unlucky sequencing.
What do p5 and p95 mean?+
They are the 5th and 95th percentiles of the 1,000 final balances. One run in twenty ended at or below the p5 value, and one in twenty ended at or above p95. The band between them covers 90% of simulated outcomes — a realistic best-to-worst range for your stats.
Why do my results change when I press Re-run?+
Re-run draws a fresh set of 1,000 random sequences from the same win rate and win/loss sizes. The individual paths change, but the summary statistics — median, p5, p95, drawdown percentiles — should stay very similar. If a stat swings a lot between re-runs, that itself is a sign your sample is volatile.
Does this simulator account for compounding or position sizing?+
No — deliberately. It uses a fixed-dollar model where every trade adds your average win or subtracts your average loss. That isolates the effect of sequencing on a constant edge. Percentage-based sizing would compound and change the distribution's shape.
How many trades should I simulate per run?+
Match it to a horizon you care about. If you take 5 trades a week, 100 trades is roughly five months. The cap is 500 trades per run so the 1,000-run simulation stays instant in your browser.
KEEP GOING
Risk management
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Enter your account size, risk percentage, entry, and stop — get the exact position size and dollars at risk.
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Kelly Criterion Calculator
Mathematically optimal bet sizing from your win rate and win/loss ratio — with full, half, and quarter Kelly.
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Drawdown Recovery Calculator
See the gain a drawdown really demands, and a realistic timeline to recover it from your own stats.
OpenStop guessing your stats. Measure them.
TerraTrade computes your real win rate, average win/loss, and expectancy from every trade you take — the exact inputs this simulator needs, straight from your journal.
Essential $29/mo · Pro $49/mo · Ultra $89/mo