Graph of data that shows growth of small cap vs large cap

Investment portfolios, why the academics matter

The Fama-French Three-Factor Model, devised by esteemed economists Eugene Fama and Kenneth French in 1992, revolutionized the understanding of asset pricing and portfolio management. This model extends beyond the traditional Capital Asset Pricing Model (CAPM) by incorporating additional factors that better capture the intricacies of stock returns. Let’s delve into a comprehensive breakdown of this influential model.

  1. The Market Factor (Market Minus Risk-Free)

– The core tenet of the Fama-French model is the inclusion of the market risk factor, which represents the excess return of the market over the risk-free rate. It acknowledges that stock returns are influenced by overall market movements.

– This factor encapsulates the systematic risk inherent in investing in the broader market. It captures fluctuations in the overall economy and market sentiment, reflecting macroeconomic factors such as interest rates, inflation, and geopolitical events.

– Investors demand compensation for bearing this systematic risk, and the market factor quantifies this premium. It forms the foundation of modern portfolio theory and asset pricing, anchoring portfolio construction and risk management practices.


  1. The Size Factor (Small Minus Big)

– Fama and French identified empirical evidence suggesting that smaller companies tend to outperform larger ones over the long term, a phenomenon not adequately explained by the CAPM.

– The size factor captures the excess returns of small-cap stocks over large-cap stocks, reflecting the risk associated with investing in smaller, less-established companies. This risk can stem from factors such as limited resources, lower liquidity, and heightened volatility.

– Investors demanding higher returns for investing in smaller firms are compensated through the size factor, which acknowledges the additional risk inherent in these investments. It underscores the importance of considering company size in portfolio construction and asset allocation decisions.


  1. The Value Factor (High Minus Low)

– Building upon their research, Fama and French observed that stocks with lower valuation metrics, such as high book-to-market ratios, consistently outperformed those with higher valuations.

– The value factor captures the excess returns of value stocks (those with lower relative prices) above growth stocks (those with higher relative prices), reflecting the premium associated with investing in undervalued securities.

– Investors demand compensation for the perceived risk of investing in value stocks, which may be undervalued for reasons such as temporary setbacks, market pessimism, or industry trends. The value factor quantifies this premium, highlighting the potential for enhanced returns through value-oriented investing strategies.


Data Sample

The data graph shows an example of how small cap value has outperformed the large cap growth (S&P 500) from the time that we have reliable data to measure the returns ( in this case since 1927) and it’s outperformed by quite a large margin. The risk associated with investing in smaller companies shows up in the added reward from the returns. Doing small samples of data can skew the overall understanding of returns as can be seen since 2010 where the S&P 500 has done better than the small value index and then on the flipside during the 10 years from 2000-2009 where many investors saw little to no return the small value index created a 12.3% return, and the large growth S&P 500 was slightly negative.

Graph of data that shows  growth of small cap vs large cap

In essence, the Fama-French Three-Factor Model provides a robust framework for understanding asset pricing and evaluating portfolio performance. By accounting for market risk, company size, and value characteristics, this model enhances our ability to construct diversified portfolios that capture risk premiums and strive for optimal risk-adjusted returns. However, it’s crucial to recognize that financial markets are dynamic, and ongoing research continues to refine our understanding of asset pricing and investment strategies.

At our financial advisor office here in Honolulu we strive to capture all of this within the portfolios and help our clients fully understand the importance of portfolio engineering. As financial advisors we furthermore look at the Portfolio turnover which is done by measuring the frequency of securities trading within a fund over a specified period and it is another very important aspect of portfolio structuring. Heightened turnover not only inflates trading expenses, elevating overall fund costs, but also increases the likelihood of triggering capital gains taxes. These taxes, imposed on profits from securities sales within the fund, can significantly erode returns and dampen overall performance. The essential aspect of this lies in striking a balance between investment strategies and tax-conscious practices to navigate the intricacies of portfolio turnover, minimizing tax liabilities while optimizing financial returns.

Portfolio Rebalancing

Maintaining a balanced portfolio is not merely a matter of initial allocation but a continuous process of adjustment and realignment to uphold the desired distribution across sectors and asset classes. The importance of rebalancing emerges as a cornerstone principle in our portfolio management. By adhering to the initial percentage setup for each sector and maintaining the desired balance between stocks and bonds, investors can harness the benefits of diversification while managing risk. Over time, market fluctuations can tilt the portfolio’s composition, leading to unintended overexposure to certain sectors or asset classes. Rebalancing acts as a corrective measure, ensuring that the portfolio remains aligned with the investor’s risk tolerance and long-term goals. Moreover, consistent rebalancing facilitates the opportunity to capitalize on market inefficiencies, buying undervalued assets and selling overvalued ones, thereby enhancing returns. This disciplined approach not only furthers portfolio stability but also instills confidence in investors, knowing that their investments are being managed in accordance with the portfolio objectives. The importance of rebalancing a portfolio lies in its ability to uphold the intended asset allocation, mitigate risk, and optimize returns over the investment horizon.

Combining all the engineering and science into a fully diversified portfolio will create an investment portfolio that increases the chance of long-term success without taking on unnecessary risk.


Diversification holds a foundation in investment management. Research underscores the importance of extending investments across various assets to mitigate risk and enhance returns. Diversification operates on the assertion that individual assets exhibit unique risk, which can be diversified away when combined with other assets in a portfolio. By allocating capital across several sectors, industries, and asset classes, investors can reduce the impact of adverse events specific to any one investment, thus shielding their portfolios from expressive losses. Portfolio research further emphasizes that the benefits of diversification extend beyond risk reduction to encompass potential return enhancement. Through diversification, investors gain revealing to a broader array of investment opportunities, capturing the potential upside of different market segments while minimizing the impact of downturns in any single sector. Additionally, diversification helps investors navigate the unpredictability of financial markets, providing a buffer against volatility and enhancing the overall stability of the portfolio. The importance of diversification lies in its ability to simultaneously manage risk and optimize returns, enabling investors to navigate the challenges of the investment landscape with confidence and resilience.


Sources:  A Five-Factor Asset Pricing Model ( 2013) 


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