A simulated portfolio deliberately based on stale price data — a Rip Van Winkle index fund — has both substantially higher performance and lower volatility than a portfolio that uses up-to-date cap weights. This holds true over the past 67 years in the United States and over shorter...

Factor returns, net of changes in valuation levels, are much lower than recent performance suggests. Value-add can be structural, and thus reliably repeatable, or situational—a product of rising valuations—likely neither sustainable nor repeatable. Many investors are performance chasers who...

In our paper — “How Can ‘Smart Beta' Go Horribly Wrong?” — we show, using U.S. data, that the relative valuation of a strategy (in comparison with its own historical norms) is correlated with the strategy's subsequent return at a five-year horizon. The high past performance of many of...

In a series of papers we published in 2016, we show that relative valuations predict subsequent returns for both factors and smart beta strategies in exactly the same way price matters in stock selection and asset allocation. To many, one surprising revelation in that series is that a number of...