Position Sizing Basics

In 30 seconds

  • Learn how to determine appropriate position sizes for your portfolio and risk tolerance.
  • Category: position
  • Uses 1 tool(s) for analysis

Learn how to determine appropriate position sizes for your portfolio and risk tolerance.

Why Position Sizing Matters

Position sizing determines how much capital you allocate to each investment. Too much concentration increases risk; too little diversification limits potential returns.

Proper position sizing helps you manage portfolio risk, avoid overexposure to single positions, and maintain discipline during market volatility.

Common Position Sizing Methods

Equal weighting: Allocate the same dollar amount to each position. Simple but may not reflect risk differences.

Risk-based sizing: Adjust position size based on individual stock volatility or beta. Higher risk = smaller position.

Conviction-based: Size positions based on confidence level, while respecting maximum position limits (e.g., 10% per stock).

Example: Position Sizing a $100,000 Portfolio

You want to add a tech stock with 30% volatility to a portfolio currently worth $100,000.

  • 1.Set maximum position limit: 10% of portfolio = $10,000
  • 2.Adjust for volatility: If average stock is 20% volatility, reduce this by 30%/20% = 1.5x adjustment
  • 3.Final position size: $10,000 / 1.5 = $6,666
  • 4.This maintains consistent risk exposure across your portfolio
Try it in the calculator →

Key Concepts

Portfolio Concentration

The percentage of total portfolio value in a single position. Many investors limit to 5-10% per stock to manage concentration risk.

Volatility Adjustment

Reduce position size for high-volatility stocks to maintain consistent risk levels across your portfolio.

Rebalancing Trigger

Set rules for when to trim or add to positions (e.g., when any position exceeds 15% due to gains).

Quick Links

Related Resources