We have observed that additions and deletions to the S&P 500 Index follow a dependable pattern: additions underperform and deletions overperform over the subsequent 12-month period.

Climate research informs us that in 2017 anthropogenic global warming reached1.0° C above pre-industrial levels (IPCC, 2018).

In late 2020, a new kid emerged on the bargain-of-the-decade block. UK stocks, and notably UK value, reached very cheap levels relative to value stocks in other developed economies. Today, UK value remains at remarkably low valuations relative to most of its fundamentals.

Rob Arnott: “There hasn’t been a better time to be a value investor at any other time in my career. I look back at the tech bubble and I never thought I would see valuations stretched the way they were then. We're back to that, and then some." We invite you to revisit “Reports of Value’s Death Have Been Greatly Exaggerated” now published in the Financial Analysts Journal.

By buying or overweighting characteristics-based factor exposure and selling or underweighting beta-based factor exposure, investors can position their portfolios to reap the rewards of factor investing while bearing less risk.

On December 21, Tesla will be the largest company ever to enter the S&P 500 Index. Tesla’s skyhigh valuation, which meets our real-time definition of a bubble, conforms to the observation that market-cap-weighted indices buy high and sell low—the antithesis of prudent investing.

The Fama–French value factor, and value investing in general, has suffered an extraordinarily long 13.3 years of underperformance relative to the growth investing style. The current drawdown has been by far the longest as well as the largest since July 1963. Arnott, Harvey, Kalesnik, and Linnainmaa examine the potential causes of value’s underperformance and provide estimates of value’s performance relative to growth’s performance under different revaluation scenarios over the next decade.

The current drawdown has been by far the longest as well as the second largest since July 1963, eclipsed only by the tech bubble from 1997 to 2000. Arnott, Harvey, Kalesnik, and Linnainmaa examine the potential causes of value’s underperformance and provide estimates of value’s performance relative to growth’s performance under different revaluation scenarios over the next decade.

Factor investing, an investment approach which targets specific stock characteristics such as value or momentum, is becoming a stronghold of investor portfolios.

Evidence shows that the yield-curve slope and equity returns provide signals of similar direction in the economy, allowing investors to nowcast with relative confidence. Today, those signals indicate that several developed markets—in particular, Japan, Germany, and the United States—are ominously close to entering a correction phase.

Traditional index funds match market performance and have negligible trading costs with low tracking error—or do they? Not actually—they routinely buy after high price appreciation and sell after high price depreciation. They also have significant trading costs from adding and deleting stocks. We show how index providers can construct better-performing indices that are less prone to performance chasing and have lower turnover.

Beware the consequences of assuming that elevated CAPE ratios are here to stay, but if they are the "new normal," low future returns are likely to be the "new normal" as well.

Momentum is one of the most compelling factors in theoretical long–short paper portfolios, but live results of momentum strategies fall short of theoretical returns. Thoughtful implementation, a careful sell discipline, and an avoidance of stocks with stale momentum can narrow the gap between paper and live results.

We demonstrate a smart beta that produces positive excess returns from sustainably faster growth in EPS. This simple, systematic strategy represents a significant improvement from today’s growth indices that fail to produce faster growth in EPS and have provided negative excess returns.

An analysis of five international stock markets indicates that published findings of a correlation between US stock returns and the political party in the White House are spurious, highlighting the importance of caution in interpreting historical investment data.

Our analysis of three first-generation smart beta strategies shows factor-replicated portfolios are ineffective substitutes for their smart beta counterparts, exhibiting poorer performance, high turnover, and low capacity.

In 2016, Research Affiliates published a series of articles challenging the “smart beta” revolution. We pointed out that, while there is merit in many factor tilt and smart beta strategies, performance chasing in these strategies—buying the popular outperforming strategies whose relative valuations are at extremely high levels—can be just as dangerous as performance chasing in other realms of asset management.

In a series of articles 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.

It may not be my money, but it is my job. — Charles Ellis in Investment Policy: How to Win the Loser's Game