ABNORMAL RETURN

Summary

Abnormal return measures how much better or worse an investment performed compared to what was expected based on its risk level or a relevant benchmark (like the S&P 500). It's calculated by subtracting the expected return from the actual return. A positive abnormal return means the asset outperformed expectations, while a negative abnormal return indicates underperformance. This concept is crucial in finance for evaluating investment performance, manager skill, and market efficiency.

Usage Context

Understanding abnormal returns is essential when studying portfolio performance evaluation, market efficiency, event studies, and investment manager assessment. It's particularly important in topics covering the Capital Asset Pricing Model (CAPM), alpha generation, and performance attribution analysis.

Common Confusions

• Confusing abnormal return with absolute return or total return
• Not understanding that abnormal return is relative to expectations, not absolute performance
• Thinking negative abnormal returns are always losses (they could still be positive returns, just below expectations)
• Mixing up abnormal return with volatility or risk measures