Big Ideas

When should an investor favor picking individual stocks over holding a stock index fund? In their November 2012 paper entitled “On Diversification”, Ben Jacobsen and Frans de Roon derive from Modern Portfolio Theory simple rules to compare concentrated investment in a portfolio of one or a few stocks to a broad, diversified (value-weighted) benchmark portfolio. The essential rule is that a concentrated portfolio is preferable to the benchmark portfolio if the product of its expected Sharpe ratio and the expected correlation of its returns with the benchmark’s returns exceeds the expected Sharpe ratio of the benchmark. They apply derivative thumb rules to real stocks to determine conditions under which stock picking is preferable to buying and holding a diversified benchmark portfolio. Using theoretical derivations and monthly returns and fundamentals for the 500 largest non-financial companies as of the end of the sample period with a history of at least five years during 1926 through 2011, they find that: Keep Reading

Nassim Taleb introduces his 2012 book, Antifragile, Things That Gain from Disorder, as “…my central work. I’ve had only one master idea, each time taken to the next step, the last step–this book–being more like a big jump. I am reconnected to my ‘practical self,’ my soul of a practitioner, as this is a merger of my entire history as practitioner and ‘volatility specialist’ combined with my intellectual and philosophical interests in randomness and uncertainty… …the relationship of this book to The Black Swan would be as follows:…Antifragile would be the main volume and The Black Swan its backup of sorts, and a theoretical one, perhaps even its junior appendix. Why? Because The Black Swan (and its predecessor, Fooled by Randomness) were written to convince us of a dire situation, and worked hard at it; this one starts from the position that one does not need convincing that (a) Black Swans dominate society and history (and people, because of ex post rationalization, think themselves capable of understanding them); (b) as a consequence, we don’t quite know what’s going on, particularly under severe nonlinearities…” For investors, key points are: Keep Reading

How can equity weighting strategies and their opposites both outperform the stock market? In the October 2012 version of their paper entitled “The Surprising ‘Alpha’ from Malkiel’s Monkey and Upside-down Strategies”, Rob Arnott, Jason Hsu, Vitali Kalesnik and Phil Tindall challenge beliefs underlying a variety of stock investment strategies that beat a capitalization-weighted benchmark by examining the performance of portfolios based on opposite beliefs. If the original beliefs determine success, then their opposites should underperform. They limit their investigation to long-only stock weightings based on original beliefs and opposites based on inverse weights or complement weights. To ensure portfolio feasibility, they restrict U.S. and global universes to large-capitalization stocks. They reform portfolios at the end of each year. When needed in portfolio construction, they estimate historical parameters (such as volatility) using five years of lagged monthly data. They consider capitalization-weighted, equal-weighted and diversity-weighted benchmarks and use a conventional four-factor (market, size, book-to-market and momentum) model to calculate strategy alphas. They ignore trading frictions. Using monthly returns for the top 1,000 U.S. stocks by market capitalization during 1964 through 2010 and for large-capitalization global stocks during 1991 through 2010, they find that: Keep Reading

Does demand for high-beta stocks by money managers extinguish the risk-return relationship? In his May 2012 paper entitled “Agency-Based Asset Pricing and the Beta Anomaly”, David Blitz investigates whether a volatility preference among stock portfolio managers flattens any relationship between beta and expected returns, thereby invalidating the most widely used asset pricing models. Because institutional investors typically evaluate portfolio managers versus market returns and prohibit or limit leverage, these managers have an incentive (under a belief in reward-for-risk) to focus investments in high-beta stocks with high expected returns. He calculates beta of a stock by regressing its monthly returns (in excess of the risk-free rate) against stock market excess monthly returns over the prior 60 months. Using monthly returns and characteristics for a broad sample of U.S. common stocks during July 1926 through December 2010, along with various benchmark data, he finds that: Keep Reading

What is the big picture on stock return predictors? In their May 2012 paper entitled “The Supraview of Return Predictive Signals”, Jeremiah Green, John Hand and Frank Zhang examine aggregate characteristics of 333 signals for which formal research indicates power to predict stock returns. They categorize each signal as accounting-based (from firm financial statements, such as accruals), finance-based (directly or indirectly from stock prices, such as return momentum) or other-based (such as stock buybacks). They standardize across studies via annualization by multiplying daily, weekly, monthly and quarterly returns by 250, 52, 12 and 4, respectively. They compile equal-weighted returns and value-weighted returns separately. They focus on Sharpe ratio as a widely used metric for comparing investment performance. Using a database of predictive signals as published in top-tier U.S. accounting, finance and practitioner journals and as disseminated in academic working papers via the Social Science Research Network (SSRN) during 1970 through 2010, they conclude that: Keep Reading

Is there a “correct” (or at least most correct) view of how financial markets work? If so, why do the beliefs of market participants, sophisticated and naive, never converge narrowly to that view? Why do investors disagree so much all the time? The following items offer some ideas, from a generally behavioral perspective, on the persistence of diversity in investor/trader beliefs. Specifically: Keep Reading

How can low-frequency traders save their microscalps from high-frequency traders? In the March 2012 version of their paper entitled “The Volume Clock: Insights into the High Frequency Paradigm”, David Easley, Marcos Lopez de Prado and Maureen O’Hara explore high-frequency trading (HFT) as volume-metered or transaction-metered (rather than time-metered) exploitation of market order processing rules and trading behaviors of others (market microstructure). Low-frequency traders focus on return drivers associated with economic/monetary policy, asset allocation and valuation methods. High-frequency traders fixate on exchange order matching engines, network connections, machine learning, order placement delays and game theory. When market microstructures differ (as for seemingly similar cash and futures equity index markets), HFT strategies differ. Based on relevant research, they conclude that: Keep Reading

Michael Dever (founder of Brandywine Asset Management) introduces his 2011 book, Jackass Investing: Don’t Do It, Profit from It, by stating: “…this book is designed to comfortably provide novice investors with a plan to follow to manage their money – one that they are unlikely to encounter if they are only exposed to the conventional financial wisdom. It’s also intended to provide a rational alternative to the beliefs of experienced investors who may have fallen prey to the myths; written to help you to specifically exploit some of the countless opportunities that are ignored by, and very often created by, the mass of irrational investors who litter the virtual Wall Street landscape. …the most important theme of them all is the fallacy of the myth that ‘There is No Free Lunch.’ In fact there is a free lunch, a veritable free threecourse buffet. It’s called true portfolio diversification…a systematic process that results in a truly balanced diversified portfolio whose returns are derived from a multitude of return drivers.” Using anecdotes and references to some relevant research in describing and refuting financial market myths, he concludes that: Keep Reading

Are low trading frictions, high trading speed and proliferation of trading strategies elevating market efficiency and thereby extinguishing U.S. stock anomalies? In their March 2012 paper entitled “Trends in the Cross-Section of Expected Stock Returns”, Tarun Chordia, Avanidhar Subrahmanyam and Qing Tong examine the evolution of individual U.S. stock return predictability based on stock/firm characteristics found in the past (mostly during the 1990s) to have predictive power. Characteristics considered include: size; book-to-market ratio; share turnover; cumulative return over five months ending one month ago; cumulative return over six months ending six months ago; monthly return reversal; stock illiquidity; stock price; analyst forecast dispersion; standardized unexpected earnings; and, accounting accruals. They test anomaly evolution across two subperiods using both regressions and long-short portfolios. Using data as available for NYSE-AMEX common stocks during 1976-2009 (with equal subperiods 1976-1992 and 1993- 2009) and for NASDAQ commons stocks during 1983-2009 (with comparable subperiods 1983-1992 and 1993-2009), they find that: Keep Reading

What do three prominent academic experts conclude when they review the body of evidence for and against the Efficient Markets Hypothesis (EMH), and therefore the potential benefit of speculation? In the April 2011 version of their paper entitled “Review of the Efficient Market Theory and Evidence”, Andrew Ang, William Goetzmann and Stephen Schaefer review the theoretical and empirical literature on EMH, with focus on implications for active investment management. They consider a range of markets and tests of both prices and investment managers, noting that EMH has evolved to consider the costs of collecting, analyzing and exploiting market information (trading frictions, financing costs, manager fees). Based on this literature review, they conclude that: Keep Reading