Active and Passive Investing

Markets Becoming More Efficient: The Disappearing Index Effect

Greenwood and Sammon’s findings of a disappearing index effect provides further support for the findings of McLean and Pontiff, Does Academic Research Destroy Stock Return Predictability? 2016. Once anomalies are well recognized by the market they decline and may even disappear, though limits to arbitrage can allow them to persist. Their findings also provide support for Andrew Lo’s The Adaptive Markets Hypothesis (2004). The bottom line is that markets are becoming more efficient, raising the hurdles for active managers to generate alpha.

Analysts set price targets using trailing P/E ratios

Trailing twelve-month P/E ratios account for 91% of the variation in analysts’ price targets. We construct a new kind of asset-pricing model around this fact and show that it explains the market response to earnings surprises.

Social Media: The Value of Seeking Alpha’s Recommendations

The finding that the recommendations from SA articles resulted in statistically significant risk-adjusted alphas (returns unexplained by conventional academic models using factors such as the market, size, value, momentum, profitability, and quality for equity portfolios) is surprising given that the empirical evidence shows how difficult it is for institutional investors such as mutual funds to show outperformance beyond the randomly expected (as can be seen in the annual SPIVA Scorecards) because of market efficiency.

Tracking Error is a Feature, Not a Bug

The benefits of diversification are well known. In fact, it’s been called the only free lunch in investing. Investors who seek to benefit from diversification of the sources of risk and return of their portfolios must accept that adding unique sources of risk means that their portfolio will inevitably experience what is called tracking error—a financial term used as a measure of the performance of a portfolio relative to the performance of a benchmark, such as the S&P 500.

Trend to Passive Investing Negatively Affecting Active Funds

While the evidence makes clear that active management is a loser’s game (one that it is possible to win but so unlikely you should not try), we don’t want active managers to disappear. Hope should continue to triumph over evidence, wisdom, and experience because active managers help eliminate market anomalies and inefficiencies created by the misbehavior of investors (such as noise traders). That helps to ensure that capital is allocated efficiently.

Diseconomies of Scale in Investing

While the research shows that fund managers are skilled, skill doesn’t translate into outperformance due to the diseconomies of scale.

Investor demand, rating reform and equity returns

The traditional financial theory attributes security returns to market- or factor-based risk, with no role ascribed to other influences. In this research, the authors argue for including investor demand as an additional variable in explaining returns.  Can changes in investor demand generate systematic changes in security returns?

Bigger is Not Always Better in Asset Management

Pastor, Stambaugh, and Taylor (2015) and Zhu (2018) provide significant evidence of decreasing returns to scale (DRS) at both the fund and industry levels. The authors examine the robustness of their inferences after Adams, Hayunga, and Mansi (2021) critique the above two studies.

Has the Stock Market Systematically Changed?

This time is almost always different, it seems, but the data suggest that things are typically always the same: chaotic and volatile. Stock market investors should be prepared for large short-term moves in stocks and they should be skeptical of narratives suggesting a causal relationship between environmental variables and future volatility.

Is Passive Ownership Bigger than Estimated?

We estimate that passive investors held at least 37.8% of the US stock market in 2020. This estimate is based on the closing volumes of index additions and deletions on reconstitution days. 37.8% is more than double the widely accepted previous value of 15%, which represents the combined holdings of all index funds. What’s more, 37.8% is a lower bound. The true passive-ownership share for the US stock market must be higher. This result suggests that index membership is the single most important consideration when modeling investors’ portfolio choice. In addition, existing models studying the rise of passive investing give no hint that prior estimates for the passive-ownership share were 50% too small. The size of this oversight restricts how useful these models can be for policymakers.

Does Emerging Markets Investing Make Sense?

The analysis above suggests that portfolios that include or exclude emerging allocations are roughly the same. For some readers, this may be a surprise, but for many readers, this may not be "news." That said, even if the data don't strictly justify an Emerging allocation, the first principle of "stay diversified" might be enough to make an allocation.

Of course, the assumptions always matter.

Visualizing the Robustness of the US Equity ETF Market

Market commentators sometimes suggest that the equity ETF market is just a bunch of "index funds" that all do essentially the same thing: deliver undifferentiated stock market exposure.

How true is that statement? Fortunately, we can test the hypothesis that the ETF market is roughly a few thousand different ways to capture the same basic risk/returns. To do so, we leverage our Portfolio Architect tool to quantify the active share of all US equity ETFs against the S&P 500 index (the king of indexes).

How Active Mutual Funds Use ETFs

In this paper we discuss the academic research about how active mutual funds use ETFs for the purpose of improving the operations of the fund, [...]

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