Sizing a position so the rules do not size it for you

Binary contracts have a property ordinary assets do not: the worst case is knowable to the cent before you click. A contract bought at 40¢ can lose exactly 40¢ and no more. That makes sizing an arithmetic problem rather than a judgement call.

What the cap allows

Each plan caps what you can have at risk in any one market. On 25K Evaluation (1-step) that is 2% of the STARTING balance — $500 — and it is measured against the starting balance for the life of the account, so it does not grow as you profit. It counts everything pointed at that market at once: the position you hold plus any open buy orders plus the one you are placing, which closes the split-it-into-five-orders route around it. An order that would cross the line is rejected before it fills rather than unwound afterwards, and it never blocks a sell.

Notice that the max-loss column is the same at every price and the contract count is not. A cheap contract does not let you risk less — it lets you buy more of the same risk. Sizing by dollars at risk is the only version of this that behaves.

Size against the floor, not against the balance

The number that ends your account is not your balance, it is your distance to the binding floor. On 25K Evaluation (1-step) you start with $1,000 of room. A full-size position at the cap is therefore a meaningful share of everything you have, and two of them held at once can be most of it.