What is position sizing in trading?

Position sizing is the process of determining how many units of a financial instrument to buy or sell in a single trade. It is a fundamental component of risk management that dictates the size of a position based on the total capital available and the trader's risk tolerance. The primary goal is to prevent a single losing trade from causing significant damage to the overall account balance. Most professional traders limit their risk per trade to 1% or 2% of their total account equity. For example, if a trader has a $10,000 account and chooses a 1% risk limit, they can afford to lose $100 on a trade. If the stop-loss order is set 10 points away from the entry price, the trader calculates the position size by dividing the $100 risk by the 10-point stop distance. This results in a position size of 10 units. Effective position sizing accounts for volatility and the distance to a stop-loss order rather than just the number of shares or contracts. By adjusting the size based on these variables, traders maintain consistent risk exposure regardless of market conditions. Trading involves substantial risk of loss, and improper position sizing can lead to rapid account depletion.