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Risk of Ruin Calculator

Monte-Carlo odds your edge survives.

Estimated risk of ruin
Median final equity
Runs that profited
Expectancy / trade

Educational tool only — not financial advice. Verify figures with your broker.

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What is the Risk of Ruin Calculator?

The Risk of Ruin Calculator is a Monte-Carlo probability tool that estimates the odds an account is wiped out (or hits a defined loss threshold) given a win rate, a reward-to-risk profile, and a risk-per-trade. It runs many simulated sequences of trades and reports how often the equity path ends in ruin. It answers: given these inputs, how fragile is the account? It estimates survival odds; it does not estimate profit.

How to use it

  1. Enter your win rate, your average win and average loss (or reward-to-risk), and the fraction of equity risked per trade.
  2. Set the ruin threshold (for example a total wipe-out or a maximum tolerable drawdown) if the tool exposes it.
  3. Let the tool run its Monte-Carlo pass (around 2,000 simulated runs) of random trade sequences from your inputs.
  4. Read the highlighted result: the estimated probability that a sequence ends in ruin.
  5. Lower the risk-per-trade or improve the inputs and re-run to see how the ruin probability responds.

How it's calculated

The tool uses Monte-Carlo simulation: it generates thousands of trade sequences where each trade is a random win or loss at your stated win rate, applying your win/loss sizes and per-trade risk to a running equity balance, and counts the fraction of runs that cross the ruin threshold. This numerical approach approximates the classic risk-of-ruin result (which for symmetric bets tends toward ((1 - edge)/(1 + edge)) raised to the number of units of capital) while handling uneven win/loss sizes and finite bankrolls that closed formulas struggle with.

Frequently asked

What is an acceptable risk of ruin?

Risk-averse traders often want it very low, but there is no official threshold; the acceptable level is a personal decision. The risk of ruin calculator reports the probability so you can judge it against your own tolerance.

Does a low risk of ruin mean my strategy is profitable?

No. A low ruin probability only means the account is statistically unlikely to be wiped out under the assumptions you entered; it says nothing about expected returns. Survival and profitability are different questions.

Why does risk of ruin use Monte-Carlo simulation?

Because real trading has uneven win and loss sizes and a finite bankroll, closed-form formulas get unwieldy. Simulating thousands of random runs estimates the odds directly from your inputs.

What does the 2,000 runs figure mean?

It is the number of independent simulated trade sequences the tool averages over to estimate the probability. More runs give a steadier estimate, though the result is still an estimate, not an exact figure.

Keep in mind: The probability is only as good as the assumptions fed in: it treats trades as independent draws at a fixed win rate, which ignores changing market regimes, correlated positions, slippage, and losing streaks that cluster in real accounts. A low risk-of-ruin estimate is not a safety guarantee, and the tool never implies the strategy will be profitable, only that it may or may not survive under idealized conditions.

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