In a challenge, the loss limit is written in the terms. Risk management means deciding, before each trade, how much you accept to lose, and deriving the position size from it. This guide explains the calculation. It does not say which level of risk suits anyone: that is a personal decision, and no result is guaranteed.
Three notions not to mix up
- Risk per trade: the maximum planned loss if the stop is hit, expressed as an amount or as a percentage of the account.
- Position size: the number of lots, contracts or units, derived from the risk per trade and the stop distance.
- Account limits: the drawdown and daily loss imposed by the firm.
Risk per trade is your choice. The account limits are the firm's. The link between the two determines how many consecutive losses the account can take.
The position size calculation
General formula:
size = risk per trade ÷ (stop distance × value of one point per unit)
Risk per trade is set first. The stop distance comes from the analysis of the trade. The size is the result, not a starting point.
Worked example (illustrative)
All values below are invented to show the arithmetic. They describe no firm and are not recommendations.
Assumptions: a 10,000 account; a maximum daily loss of 500; a maximum overall loss of 1,000 (static threshold); risk per trade set at 1% of the account, i.e. 100; a stop 25 points away; a point value of 2 per lot.
- Size: 100 ÷ (25 × 2) = 2 lots.
- Five losing trades of 100 each: 500. The daily limit is reached on the fifth.
- Ten losing trades of 100: 1,000. The overall limit is reached.
- With a risk of 0.5% (50 per trade): ten consecutive losses in one day to reach 500, twenty to reach 1,000.
The calculation shows the link: the higher the risk per trade relative to the limits, the fewer losses it takes to close the account. It says nothing about the probability of hitting those losses in a row.
A loss needs a larger gain to recover
Losing 10% of a balance brings it to 90% of its value. Getting back to the starting point takes 1 ÷ 0.9 = 1.111, a gain of about 11.1%. Losing 20% requires a gain of 25%. The gap grows with the loss, which is an arithmetic reason to limit risk per trade.
Checking the calculation against costs
The real loss of a losing trade includes the loss at the stop, but also the spread and commissions. If the commission is 1 per lot and the position is 2 lots, it adds 2 to the 100 loss of the example: 102 in total. Include these costs in the risk per trade, especially when the limits leave little room.
Linking risk to the firm's rules
- Trailing drawdown: the remaining room matters more than the nominal account size. After a rise, the threshold moves up (see rules explained); risk per trade should be compared with the remaining room, not with the starting capital.
- Daily loss: it limits the number of losing trades in a day. Plan to stop the day before the limit, not at the limit.
- Slippage and fees: an actual loss can exceed the planned loss at the stop. Keep a margin between your planned risk and the limit.
- Multiple positions: several correlated positions (same direction on close instruments) add up in practice. Their combined risk counts, not that of each.
- Open positions and intraday: if the limit is measured in real time, the unrealized result counts (see drawdown).
A written plan before you start
A risk plan fits in a few lines, written before the challenge:
- Maximum risk per trade (amount).
- Maximum number of losing trades before stopping for the day.
- The loss after which you stop trading until the next day.
- What is prohibited: increasing size after a loss, moving a stop to avoid a loss, trading without a stop.
- The firm's rules to check every day (reset time, announcements).
The plan reduces the effect of psychological biases; it does not guarantee a gain. It can be tested on a simulation account before paying any fee.
Key points
- Position size is derived from the chosen risk and the stop distance.
- The firm's limits set how many losses the account can take.
- A worked example is not a probability.
- No level of risk protects against a loss.
For a list of mistakes to avoid, see beginner mistakes. Terms: glossary. Framework: risk warning.
The proproaster editorial team