Monte Carlo Simulation for Trading Strategies: Why One Backtest Is Never Enough

A smooth equity curve can create a false sense of certainty.

This does not mean that the backtest is wrong. It means that the backtest contains only one historical sequence of wins and losses. A different sequence, produced by the same underlying edge, could generate a very different drawdown and a much more difficult trading experience.

The video below provides a visual explanation of how Monte Carlo simulation helps expose this uncertainty.

Monte Carlo simulation is not an attempt to predict the next trade or the exact future balance. Its purpose is to stress-test the assumptions behind a trading strategy by generating many plausible alternative paths.

The most useful result is not necessarily the average return. More important questions include:

How deep can the drawdown become?

How long can a losing or stagnant period last?

What percentage of simulations exceed the account’s risk limit?

Would the strategy remain operational under an unfavorable sequence of trades?

In the example presented in the video, the historical drawdown was 9.9%, while the 95th-percentile simulated drawdown reached 23.9%.

The figures shown in this example are based on a hypothetical strategy created solely for educational purposes. They do not represent the historical, live, or projected performance of Varunna BTC or Arinniti Gold.

This does not automatically invalidate the strategy. It shows that position sizing based only on the historical drawdown could be dangerously optimistic.

Monte Carlo also has limitations. It can only generate scenarios based on the assumptions and distributions used in the simulation. It cannot predict structural market changes, execution problems, abnormal spreads or the permanent disappearance of a strategy’s edge.

For this reason, Monte Carlo should be used together with other validation methods, including out-of-sample testing, walk-forward analysis, execution-cost stress tests and live monitoring.

This type of analysis is used as one of the validation layers in the development and evaluation of our automated systems, including VARUNNA BTC and ARINNITI GOLD.