What is risk per trade

Risk per trade is the planned loss if a position reaches its stop. It is determined by the distance to the stop and the position size, so the effective dollar risk is stop distance multiplied by units held. Margin describes collateral, not loss at the stop. In Sonar’s framework, position sizing rules govern this risk by converting a chosen loss limit into an allowable trade size.

Risk per trade is the amount of capital a trader stands to lose if a position is exited at its stop level. In Sonar Sciences’ fundamentals material, risk is framed around the loss taken when the predefined exit is reached rather than around the capital or margin committed to open the trade.

Mechanically, risk per trade is set by two inputs: the distance from entry to the stop and the size of the position. If the stop is farther from entry, each unit of position carries more loss at the stop. If the position size is larger, the same stop distance produces a larger total loss. The dollar risk of the trade is therefore the stop distance multiplied by the number of units held.

This is why margin usage and risk per trade are different concepts. Margin is the collateral required to carry the position. Risk per trade is the loss realized if the stop is hit. A trade can use relatively little margin and still carry high risk if the position is large relative to the stop distance, and a trade can use more margin while carrying lower defined risk if the size is reduced or the stop structure changes.

Within Sonar’s research framework, position sizing is the control that determines how much capital is exposed to loss on any single trade. Sizing rules translate a chosen risk budget into a permissible number of units after accounting for the stop distance. In that setup, the trader does not begin with margin used and infer risk from it. The trader begins with a loss limit, then sizes the trade so that the maximum planned loss at the stop remains within that limit.

For quantitative traders, this distinction matters because it makes risk measurable before entry and comparable across instruments, signals, and portfolio components. Defining risk per trade as stop distance times position size gives a consistent unit of analysis for testing and portfolio construction. It also keeps focus on the rule that caps loss per position: sizing rule.

Drafted with AI assistance from cited sources. Reviewed and approved by Sonar Sciences Quant & Research Team.