01
Start with an amount you can define
Position sizing begins with a clear maximum amount of capital you are prepared to expose to a single idea. That limit should fit your circumstances, total portfolio exposure, and ability to absorb a loss.
02
Define invalidation before action
Write down what observation would show that your original reasoning no longer applies. This is not a prediction of where price will go. It is a way to avoid changing the plan only after an uncomfortable outcome.
03
Review exposure across ideas
Several positions can share the same industry, market condition, or source of risk. Looking at each position alone can hide the combined exposure. A written review helps reveal concentration before it becomes accidental.