Overview

Many quantitative equity portofolio models create return and risk forecasts using a set of statistical factors that drive the equity returns. The theory establishing such much is given in Arbitrage Pricing Theory

Factors

Equity factors are typically classified into the following three categories.

• Technical Factors
• Economic Factors
• Value and Quality Factors

The Fama/French is a famous three factor model whose effectiveness has seemed to persist over time.

Fitting

Once the risk factors have been identified, one needs to estimate an assets sensitivity (beta) to the factor in order to use the model in practice. This involves fitting the model to the available data. There are multiple techniques for fitting a model to data.

• OLS Regression
• Maximum Likelihood
• Machine Learning