WealthJot.ai

Monte Carlo Simulation

advanced7 min read

Reshuffle your trades thousands of times to see the range of outcomes luck could have dealt.

A single backtestTesting a trading strategy on historical data. shows you one path — the exact sequence of trades that happened to occur. Monte Carlo simulationReshuffling trades thousands of times to see the range of outcomes. reshuffles or resamples those trades thousands of times to reveal the full range of outcomes that luck could plausibly have produced.

The profound shift Monte CarloReshuffling trades thousands of times to see the range of outcomes. forces: *your backtestTesting a trading strategy on historical data.’s equity curveA graph of a strategy’s account value over time. is just one sample from a distribution of possible outcomes — and the order of your trades was largely luck. Your real trades arrived in a particular sequence, but they easily could have come in a different order — and a different order can mean a much* deeper drawdownThe worst peak-to-trough fall in a portfolio. or a much worse return, even with the identical set of trades. By randomly reshuffling the trade sequence (or resampling with replacement) thousands of times, Monte CarloReshuffling trades thousands of times to see the range of outcomes. builds a distribution: not “my max drawdownThe worst peak-to-trough fall in a portfolio. was 18%” but “across 10,000 plausible orderings, my drawdown was usually 15–30% and occasionally hit 40%.” This is transformative for risk understanding: it reveals the bad luck you haven’t experienced yet — the worse-but-entirely-possible paths your single backtestTesting a trading strategy on historical data. didn’t happen to show. It stops you trusting one lucky sequence and prepares you for the drawdowns the *futureA binding agreement to buy or sell at a set price on a future date.* may actually deal. You stopA pre-set exit that caps your loss if a trade goes wrong. asking “what happened?” and start asking “what could happen?”
ExampleYour backtestTesting a trading strategy on historical data. shows an 18% max drawdownThe worst peak-to-trough fall in a portfolio. — comforting. Run Monte CarloReshuffling trades thousands of times to see the range of outcomes. by reshuffling the same trades 10,000 times and you find that while the median worst drawdownThe worst peak-to-trough fall in a portfolio. is ~20%, the worst 5% of orderings hit 35–40%. Same trades, but a plausible unlucky sequence would have been far more painful — knowledge that helps you size and prepare for reality, not just the one path you saw.
Key takeawayMonte CarloReshuffling trades thousands of times to see the range of outcomes. reshuffles your trades thousands of times to reveal the range of outcomes luck could deal — because your backtestTesting a trading strategy on historical data. is just one (lucky) ordering. It produces realistic risk distributions (typical and worst-case drawdowns) and shifts you from “what happened” to “what could happen,” preparing you for unseen bad luck.
FAQs
What does Monte Carlo tell me that a normal backtest doesn’t?

It reveals the *distribution* of possible outcomes rather than the single realised path — especially the worse-but-plausible drawdowns your one backtest happened to avoid. This is invaluable for risk management and position sizing: you size for the bad luck that *could* happen, not just the specific (often lucky) sequence history dealt you.