# What Is Alpha?

In quantitative finance, “alpha” refers to a measure of an investment strategy’s performance compared to a benchmark index, after adjusting for risk. It represents the excess return generated by the strategy beyond what would be expected based on its level of risk. Alpha is often used to assess the skill or effectiveness of portfolio managers, traders, or investment strategies in generating returns.

Mathematically, alpha is typically calculated using the Capital Asset Pricing Model (CAPM) or similar models that relate an asset’s return to its level of risk. In these models, alpha is the intercept term of the regression equation, representing the excess return not explained by the systematic risk factors.

Positive alpha indicates that the trading strategy has outperformed the benchmark, while negative alpha suggests underperformance.

Alpha is a crucial concept in quantitative finance, as it helps investors evaluate the effectiveness of their investment decisions and identify sources of added value beyond market movements.

See also