AutoPilot Trader Risk Calculator & Position Sizing Guide
Position sizing decides whether an automated strategy works for you. Not the win rate, and not which build you picked. The number of contracts you run against the capital you have is what determines whether you are still trading after a bad stretch, and a bad stretch is the one thing you can count on arriving.
This guide covers how to size an AutoPilot Trader account and what the numbers mean once you have them. The calculator itself lives on the performance page, next to the record it draws from, so it always reflects the current strategies rather than a snapshot of an older build.
Set your account size and your drawdown limit, pick a configuration, and it tells you whether that configuration would have survived the worst stretch in the record. It runs against the same daily data the published charts are built from.
Open the Risk CalculatorStart With the Drawdown, Not the Return
Most position sizing tools answer the wrong question. They tell you what you might make, which is the number you want to see and the number least able to help you. The one that decides whether you are still trading next month is the drawdown.
Here is the mechanism, and it has nothing to do with skill. Every strategy has losing stretches. If a stretch that the strategy recovers from is larger than what your account can absorb, you do not get to be there for the recovery. Either the account closes itself, in the case of a funded account with a hard limit, or you close it yourself because watching the balance fall past the point of comfort is genuinely difficult and most people stop.
Both outcomes end the same way. You take the full loss and none of the recovery. This is why sizing starts from what you can survive and works backwards to contracts, rather than starting from what you would like to earn.
Read your drawdown number honestly
The tool shows you the largest peak-to-trough loss in the record for the configuration you picked. Ask yourself one question about it: if I lost that amount over the next few weeks, would I turn the system off? If the answer is yes, you are oversized. Reduce contracts until the answer is no.
The historical worst is not a ceiling. It is the worst thing that happened in the window shown, which is a different claim from the worst thing that can happen. Size for a stretch deeper than anything in the record, because eventually there will be one.
Risk Capital Is Not Account Size
The most common sizing error has nothing to do with contracts. It is entering the wrong number in the first place.
If you trade a funded account with a maximum drawdown limit, your real risk capital is that limit. Not the account balance, not your buying power. A large account with a small trailing drawdown limit is a small account wearing a large number, and sizing to the balance rather than the limit is how those accounts close in their first month.
Enter the limit. The tool sizes against what can actually be lost before the account stops existing.
Funded accounts have a second problem. Those limits are usually enforced intraday and on a trailing basis, so an open position can breach a limit that end-of-day figures never show. Every drawdown figure published is measured on closed daily results. Size below what the tool allows rather than at it.
Why Contract Count Changes the Trade Itself
This is the part that surprises people, and it is the reason a "one contract" figure cannot be produced by dividing a three contract figure.
The strategy splits its exits across the contracts you run. At three contracts it takes a first target, a second target, and holds a runner for the extended part of a move. At two there is no runner. At one there is no first target either, so the position runs all the way to the second target or stops out.
Those are three different trades with three different shapes. The one contract version wins less often and wins larger when it does, because it never banks the early partial. Dividing a three contract result by three would describe a trade holding a runner that the one contract trader never carries, which is why every size published is its own run rather than a fraction of a larger one.
- Three contracts is the designed base unit and the size figures are quoted at.
- Multiples of three scale from that base, keeping the exit structure proportional.
- One and two contracts run a different exit structure, with their own published records.
Full-size and micro contracts are not the same instrument
A micro contract carries a tenth of the exposure of its full-size equivalent, so ten micros approximate one full contract in dollar terms. The tool has an explicit toggle because getting this wrong by a factor of ten is the most expensive arithmetic mistake available to you.
One caveat the toggle handles for you. Micro P&L is a tenth of full-size, but micro commission is nearer a third rather than a tenth, so a plain division overstates micro results. The published figures charge that difference back.
Full-size contracts and hard drawdown limits do not mix. A single full-size contract can move a limit-capped account past its floor in one ordinary session, before any strategy rule has a chance to apply. If your account has a hard floor, run micros.
Choosing Between Core and Shield
The two builds run off one engine. Core takes every qualifying setup the framework finds. Shield adds filters that pass on some of those setups, which costs it profit when conditions are good and protects it when they are not.
Choose from how your account is structured rather than from how bold you feel. An account with room to sit through a normal drawdown runs Core. An account with a hard floor, whether that is a prop evaluation, a trailing limit, or a balance small enough that one bad stretch ends the run, runs Shield.
Then leave it alone. Switching builds because the one you are running just had a bad month is the most reliable way to capture the worst of both, since you sell the bottom of one and buy the top of the other. Review the choice quarterly, not after a red week.
Running More Than One Strategy
Two strategies that lose money on the same days give an account no protection. Two that do not are how you reduce the drawdown you carry without giving up the same share of the return, and it is the main reason to run more than one.
The published drawdown for a combination is computed from the summed daily results of that exact combination, which matters more than it sounds. Strategies reach their worst stretches at different times, so adding each one's worst drawdown together produces a number substantially larger than anything the combined account would have experienced. The tool computes the real figure rather than estimating it, and the difference is the entire diversification argument.
Two constraints before you deploy a combination.
- Each strategy needs its own book at the broker. Two running on the same contract inside one account net against each other, and both then believe they still hold a position.
- On a funded account, this is a hedging risk. Two strategies that can hold opposite positions at the same time counts as hedging whether the legs sit in one account or two, and most firms treat that as a terminable violation rather than a warning. Multi-strategy setups belong on a personal account.
Four Ways People Get This Wrong
Using buying power instead of risk capital
On a funded account, enter the maximum drawdown limit rather than the account size. The limit is the number that ends the account.
Starting large and planning to scale down
By the time the evidence tells you to scale down, you have already taken the losses that produced the evidence. Start conservative and scale up out of profits.
Confusing full-size with micro contracts
Three full-size contracts and three micros are not the same position. One carries ten times the exposure of the other. Use the toggle.
Doubling contracts expecting only doubled returns
It doubles the drawdown as well, which often moves a configuration from comfortably survivable to not survivable at all. Run the new size through the tool before you trade it, not after.
Run Your Own Numbers
Everything above is the reasoning. The arithmetic is on the performance page, alongside the full record, the month-by-month results with the losing months included, and the raw data files behind every figure.
Open the Risk CalculatorPublished performance figures are simulated. Simulated results have inherent limitations: because the trades were not executed, they may under or over compensate for market factors such as liquidity, and simulated programs are designed with the benefit of hindsight. No representation is made that any account will achieve profits or losses similar to those shown. Trading futures involves substantial risk of loss and is not suitable for all investors. Nothing here is investment advice. The complete disclosure accompanies the figures on the performance page.
