New methods for defining and weighting factors can significantly enhance the benefits of factor investing. Factor-based investment strategies launched since the 1980s have generated unexpected results when the drivers of return change from one market cycle to the next. A notable example of this is the underperformance of book-to-price, or BP, since the beginning of the global financial crisis, a period during which asset-light companies have dominated returns. One of the great idioms of investing is the importance of "avoiding the rearview mirror." Applying this lesson to factor investing can provide meaningful insights to generate more consistent returns and withstand the changing market forces that shape equity returns.
As investors consider the choice of factors, they generally look to history as a guide. Countless papers have discussed the merits of blending quality, value and momentum. Theory supported by empirical evidence provides ample justification for their inclusion as factors for stock selection. Companies with rising fortunes led by high-quality management teams trading at reasonable multiples are attractive investments for both fundamental and factor-based managers.
The advantage of factor investing is its systematic approach for identifying stocks with these desirable characteristics across a broad opportunity set such as the MSCI ACWI Investable Market index. Where the process can break down, however, is in the definition of each factor. Quality, value and momentum are all multidimensional, so selecting a single dimension to measure any of these factors based on statistical significance may be appealing but can carry unwanted risks as market dynamics change.
Exhibit 1 displays the returns to book-to-price since 2001. What is remarkable is the stability of its return, first in a positive direction, followed by generally negative returns. Positive returns since the financial crisis have been limited to brief periods of economic recovery (e.g., 2009, 2016 and 2021). Are the negative returns an anomaly or are there fundamental reasons why BP has underperformed? This is an important question for both index providers and managers who employ this factor for stock selection.