Drawdown & Losing Streak Simulator

Two traders run the same system, with the same edge, the same discipline and the same risk. One finishes the year up 60% and writes a thread about process. The other is down 12%, convinced the method stopped working, and has already bought a different one. Nothing separates them except the order in which their winners and losers arrived.

This simulator makes that visible. Enter a system, and it runs hundreds or thousands of accounts through it — each with the same probabilities, each with a different random sequence — then shows you the whole distribution instead of the one comfortable average: how deep the drawdowns go, how long the losing streaks run, and how wide the gap between the lucky and unlucky version of the identical strategy really is.

How to read the four numbers that matter

Median versus the 5th percentile. The median is the outcome you plan around. The 5th percentile is the outcome you must be able to survive, because one account in twenty gets it and nothing in your behaviour decides which one you are. If a positive-expectancy system still shows a negative 5th percentile over your horizon, that is not a flawed system — it is an honest statement that your horizon is too short for the edge to assert itself.

Median drawdown versus worst-case drawdown. Traders size their risk against the drawdown they imagine, which is usually close to the median. The number that ends careers sits in the tail. Look at the 1-in-20 figure and ask a concrete question: if the account showed that number on a Wednesday afternoon, would you take the next signal exactly as written? If the answer is no, the risk percent above is already too high — not because the maths says so, but because you will not execute it.

The losing streak columns. At a 40% win rate, a run of seven or eight losses is not bad luck, it is Tuesday. Most traders abandon a working method somewhere in the middle of a perfectly normal streak, then watch it recover without them. Knowing the number in advance converts a crisis into an expected event.

What the simulation deliberately does not model

Each trade here is an independent draw with a fixed probability — the friendliest possible world. Real markets cluster: volatility regimes make losers arrive together, correlated positions turn three trades into one, and your own execution degrades exactly when the equity curve does. Slippage is not modelled, nor are gaps, nor is the very human tendency to size up after wins. Every one of those makes real drawdowns deeper than simulated ones. Treat the tail numbers here as an optimistic floor rather than a worst case.

Use it before the drawdown, not during

The productive way to use this tool is to run your actual system, write down the 1-in-20 drawdown and the 1-in-100 losing streak, and put both numbers in your trading plan as thresholds you have already agreed to trade through. A drawdown you decided about in advance is a cost of business. The same drawdown met without preparation is the moment you change the rules, and changing the rules mid-streak is what turns a normal statistical event into a permanent loss.