What is Treynor Ratio?
Mathematical Foundation
Laws & Principles
- Treynor vs. Sharpe: The key difference is the risk denominator. The Sharpe Ratio uses total standard deviation (both systematic and unsystematic risk). The Treynor Ratio uses only Beta (systematic risk). Treynor is the preferred metric when a portfolio is only one slice of a larger, fully-diversified allocation, because unsystematic risk is already eliminated by diversification.
- Beta Interpretation: A Beta of 1.2 means the portfolio historically moves 20% more than the market — up or down. A Beta of 0.7 means the portfolio is 30% less volatile than the market.
Step-by-Step Example Walkthrough
" A fund manager reports a 12% portfolio return. The risk-free rate is 4.5%. The portfolio's Beta is 1.2. "
- 1. Excess Return: 12% - 4.5% = 7.5%
- 2. Treynor Ratio: 7.5% / 1.2 = 6.25