Small Minus Big (SMB)
Small minus big (SMB) is one of the three factors in the Fama/French stock pricing model. Beyond the original three factors in the Fama/French model — the SMB, HML, and market factors — the model has been expanded to include other factors, such as momentum, quality, and low volatility. Small minus big is the excess return that smaller market capitalization companies return versus larger companies. High minus low (HML) is another factor in the model that says value stocks tend to outperform growth stocks. Small minus big (SMB) is a factor in the Fama/French stock pricing model that says smaller companies outperform larger ones over the long-term. The model essentially says there are two other factors in addition to market performance that consistently contribute to a portfolio's performance.
What Does Small Minus Big Mean?
Small minus big (SMB) is one of the three factors in the Fama/French stock pricing model. Along with other factors, SMB is used to explain portfolio returns. This factor is also referred to as the "small firm effect," or the "size effect," where size is based on a company's market capitalization.
Understanding Small Minus Big (SMB)
Small minus big is the excess return that smaller market capitalization companies return versus larger companies. The Fama/French Three-Factor Model is an extension of the Capital Asset Pricing Model (CAPM). CAPM is a one-factor model, and that factor is the performance of the market as a whole. This factor is known as the market factor. CAPM explains a portfolio's returns in terms of the amount of risk it contains relative to the market. In other words, according to CAPM, the primary explanation for the performance of a portfolio is the performance of the market as a whole.
The Fama/Three-Factor model adds two factors to CAPM. The model essentially says there are two other factors in addition to market performance that consistently contribute to a portfolio's performance. One is SMB, where if a portfolio has more small-cap companies in it, it should outperform the market over the long run.
Small Minus Big (SMB) vs. High Minus Low (HML)
The third factor in the Three-Factor model is High Minus Low (HML). "High" refers to companies with a high book value-to-market value ratio. "Low'" refers to companies with a low book value-to-market value ratio. This factor is also referred to as the "value factor" or the "value versus growth factor" because companies with a high book to market ratio are typically considered "value stocks."
Companies with a low market-to-book value are typically "growth stocks." And research has demonstrated that value stocks outperform growth stocks in the long run. So, in the long run, a portfolio with a large proportion of value stocks should outperform one with a large proportion of growth stocks.
Special Considerations
The Fama/French model can be used to evaluate a portfolio manager's returns. Essentially, if the portfolio's performance can be attributed to the three factors, then the portfolio manager has not added any value or demonstrated any skill.
This is because if the three factors can completely explain the portfolio's performance, then none of the performance can be attributed to the manager's ability. A good portfolio manager should add to a performance by picking good stocks. This outperformance is also known as "alpha."
Related terms:
Alpha
Alpha (α) , used in finance as a measure of performance, is the excess return of an investment relative to the return of a benchmark index. read more
Business Valuation , Methods, & Examples
Business valuation is the process of estimating the value of a business or company. read more
Capital Asset Pricing Model (CAPM)
The Capital Asset Pricing Model is a model that describes the relationship between risk and expected return. read more
Factor Investing
Factor investing is looks at statistical similarities among investments to identify common factors to leverage in an investing strategy. read more
Fama and French Three Factor Model
The Fama and French Three-Factor model expanded the CAPM to include size risk and value risk to explain differences in diversified portfolio returns. read more
Heteroskedastic
Heteroskedastic refers to a condition in which the variance of the residual term, or error term, in a regression model varies widely. read more
High Minus Low (HML)
High Minus Low (HML), also referred to as the value premium, is one of three factors used in the Fama-French three-factor model. read more
Market Capitalization
Market capitalization is the total dollar market value of all of a company's outstanding shares. read more
Multi-Factor Model
A multi-factor model uses many factors in its computations to explain market phenomena and/or equilibrium asset prices. read more
Small-Value Stock
Small-value stock refers to a small market capitalization stock, but the term also refers to stock that is trading at or below its book value. read more