Exposing the portfolio to a variety of factors improves diversification. The aim of diversifying according to underlying factors is to make the portfolio more robust.
Diversification using the factor approach differs from the traditional method of distribution over asset classes such as equities, bonds and private equity, commodities, hedge funds and regions. The latter approach doesn’t provide insight into the underlying factors that determine the return-risk ratio of a portfolio.
Factor investing means that we divide up a portfolio into factors with significant expected risk and/or return differentials. Accordingly, the assets in a factor-based portfolio are distributed over premiums such as low volatility, size, value and momentum.