Field notes · 27 May 2026
Position size as a consequence of stop distance, not a preference
Sizing from how much you want to make reverses the order of a sound risk plan.
A common habit among newer chart traders is to decide size first—“I always trade two contracts”—and then stretch the stop to fit. That habit quietly destroys risk-to-reward discipline. Stop distance should come from the chart. Size should follow from how much of the account you allow on that idea.
Suppose your account risk limit is 0.5% per trade. Your invalidation sits 40 points from entry. Size is then whatever quantity keeps the loss at invalidation equal to 0.5%. If that quantity feels too small to be interesting, the issue is the setup distance or the risk budget—not a reason to ignore the stop.
In Trade Management Practice Labs we freeze size at the open of each scenario. Participants then manage exits only. Removing the ability to “add because it looks good” exposes how often management decisions were really size decisions in disguise.
Write your risk percentage on the same sheet as your R:R plan. Treat it as a hard constraint for the session. After twenty practice trades, review whether your average planned R:R improved once size stopped floating.
Size is the last number you write, not the first. Chart structure sets the stop; account rules set the quantity.