Investing Expertise

Should practitioners and academics doing research on financial markets be especially careful (compared to researchers in other fields) when employing statistical inference. In the July 2021 version of their paper entitled “Finance is Not Excused: Why Finance Should Not Flout Basic Principles of Statistics”, David Bailey and Marcos Lopez de Prado argue that three aspects of financial research make it particularly prone to false discoveries:

1. Due to intense competition, the probability of finding a truly profitable investment strategy is very low.
2. True findings are often short-lived due to financial market evolution/adaptation.
3. It is impossible to verify statistical findings through controlled experiments.

Based on statistical analysis principles and their experience in performing and reviewing financial markets research, they conclude that: Keep Reading

When a public pension fund reports beating its benchmark, does that signify a job well done? In his July 2021 paper entitled “Cost, Performance, and Benchmark Bias of Public Pension Funds in the United States: An Unflattering Portrait”, Richard Ennis analyzes net returns of statewide pension funds in the U.S. He calculates both (1) net Sharpe ratio and (2) return versus a matched benchmark constructed via regression as the best-fit combination of the Russell 3000 stock index, the MSCI ACWI ex-U.S. stock index and the Bloomberg Barclays US Aggregate bond index. He compares performance relative to this benchmark and estimated costs for each fund. He then assesses performance of the funds versus the benchmarks they themselves construct and report against. Using self-reported data for a sample of 24 such funds self-reported via the Public Plans Data website during July 2010 through June 2020, he finds that: Keep Reading

Can machine learning-generated stock market crash predictions be amenable to human interpretation? In their June 2021 paper entitled “Explainable AI (XAI) Models Applied to Planning in Financial Markets”, Eric Benhamou, Jean-Jacques Ohana, David Saltiel and Beatrice Guez apply a gradient boosting decision tree (GBDT) to 150 technical, fundamental and macroeconomic inputs to generate daily predictions of short-term S&P 500 Index crashes. They define a crash as a 15-day S&P 500 Index return below its historical fifth percentile within the training dataset. The 150 model inputs encompass:

1. Risk aversion metrics such as asset class implied volatilities and credit spreads.
2. Price indicators such as returns, major stock index Sharpe ratios, distance from a long-term moving average and and equity-bond correlations.
3. Financial metrics such as 12-month sales growth and price-to-earnings ratio forecasts.
4. Macroeconomic indicators such Citigroup regional and global economic surprise indexes.
5. Technical indicators such as market breath and index put-call ratio.
6. Interest rates such as 10-year and 2-year U.S. Treasury yields and break-even inflation level.

They first rank and filter the 150 inputs based on GBDT to discard about two thirds of the variables. They then apply the Shapley value solution concept to identify the most important of the remaining variables and thereby support interpretation of methodology outputs. Using daily values of the 150 model inputs and daily S&P 500 Index roll-adjusted futures prices from the beginning of January 2003 through mid-January 2021 (with data up to January 2019 used for training, the next year for validation and the rest for testing), they find that:

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Overall, how do retail option traders perform compared to institutional counterparts, and what accounts for any performance difference? In their June 2021 paper entitled “Who Profits From Trading Options?”, Jianfeng Hu, Antonia Kirilova, Seongkyu Park and Doojin Ryu use account-level transaction data to examine trading styles and profitability by investor category for KOSPI 200 index options and futures. There are no restrictions in Korean derivatives markets on retail investor participation, and retail participation is high. Using anonymized account-level (153,835 domestic retail, 5,904 domestic institutional, 667 foreign institutional and 604 foreign retail) data for all KOSPI 200 index options and futures trades during January 2010 through June 2014, they find that:

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Why have U.S. public pension, endowment and other non-profit funds (institutional investors) consistently underperformed simple, investible passive benchmarks since 2008? How should they remedy that underperformance? In his April 2021 paper entitled “How to Improve Institutional Fund Performance”, Richard Ennis summarizes prior papers quantifying post-2008 institutional investor returns and recommends how institutions can improve this performance. Extending performance estimates from prior analyses through June 2020, he finds that: Keep Reading

A subscriber provided promotional materials for, and requested assessment of, the Artemis Capital Management Dragon portfolio. General allocations for this portfolio are:

• 24% to secular growth such as U.S. and international stocks.
• 21% to “long volatility and convex hedging” such as the Artemis Vega Fund and tail risk hedges (probably options and/or futures).
• 19% to commodity trend following.
• 18% to interest rate-sensitive assets such as U.S. Treasury bonds, Treasury Inflation-Protected Securities (TIPS) and investment grade bonds.
• 18% to inflation protection such as gold and potentially crypto-assets.

Apparently, the fund has not yet launched and all performance data are backtested (hypothetical). Lacking detail to replicate the Dragon portfolio, we look at its hypothetical monthly returns per promotional materials. We use a 60% SPDR S&P 500 Trust (SPY) – 40% iShares 20+ Year Treasury Bond (TLT) portfolio, rebalanced monthly, as a simple hybrid benchmark. For reference, we also compare results for SPY, the Simple Asset Class ETF Value Strategy (SACEVS) Best Value portfolio and the Simple Asset Class ETF Momentum Strategy (SACEMS) equal-weighted (EW) Top 2 portfolio. Using gross monthly total returns for the Dragon portfolio, SPY, TLT, SACEVS Best Value and SACEMS EW Top 2 during January 2012 through April 2021, we find that: Keep Reading

In the preface to the 2021 edition of his book, The Gone Fishin’ Portfolio: Get Wise, Get Wealthy…and Get on With Your Life, Alexander Green sets the following goal: “[S]how readers the safest, simplest way to achieve and maintain financial independence. …I’ll cover the investment basics and unite them in a simple, straightforward investment strategy that will allow you to earn higher returns with moderate risk, ultralow costs, and a minimal investment of time and energy. …Setting up the Gone Fishin’ Portfolio is a snap. Maintaining it takes less than 20 minutes a year.” Based on his 35 years of experience as an investment analyst, portfolio manager and financial writer, he concludes that:

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Should investors buy stocks of companies for which analysts have issued very high earnings growth forecasts? In the March 2021 revision of their paper entitled “Diagnostic Expectations and Stock Returns”, flagged by a subscriber, Pedro Bordalo, Nicola Gennaioli, Rafael La Porta and Andrei Shleifer update and extend prior research on the relationship between analyst long-term earnings growth forecasts and future returns of associated stocks. They define long-term forecasts as expected annual increase in operating earnings over the next three to five years. To relate these forecasts to stock returns, they each December form ten equal-weighted portfolios by ranking stocks into tenths (deciles) based on annual geometric average forecasted long-term earnings growth. They hold these portfolios until the next December, rebalancing each back to equal weight monthly. They focus on the highest long-term growth (HLTG) and lowest long-term growth (LLTG) decile portfolios. Using analyst earnings growth forecasts since December 1981 for a broad sample of U.S. common stocks and associated stock returns since December 1978, all through December 2016, they find that:

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Are stock due diligence reports posted on Reddit’s Wallstreetbets (WSB) informative? If so, do users exploit them skillfully? In their March 2021 paper entitled “Place Your Bets? The Market Consequences of Investment Advice on Reddit’s Wallstreetbets”, Daniel Bradley, Jan Hanousek Jr., Russell Jame and Zicheng Xiao examine the value and retail trading impact of single-stock due diligence reports posted on WSB. WSB now has about 9.5 million subscribers and on January 28th, 2021 generated over 271 million pageviews (trailing only Google and YouTube). The authors consider both market-adjusted returns and style-adjusted returns (DGTW-adjusted, compared to stocks matched on size, book-to-market and momentum) of due diligence report stock recommendations. Using 2,340 time-stamped due diligence reports focused on a single common stock (612 distinct stocks) and associated firm accounting data and stock price/trading data during 2018 through 2020, they find that:

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Is buying assets during banking crises, when assets appear to be at deep discounts, an attractive long-run strategy? In their January 2021 paper entitled “Investing in Crises”, Matthew Baron, Luc Laeven, Julien Penasse and Yevhenii Usenko investigate asset returns across several years before and after banking crises, for which they identify the onset (first month) in three ways:

1. Systemwide banking panics (as specified in a prior paper).
2. Multiple major government interventions (as specified in a prior paper).
3. 30% drop in a country’s bank stock index (bank equity crash).

They test trading strategies in which a U.S. investor exploits banking crises around the world as they occur and otherwise holds U.S. Treasury bills (T-bill). They focus on bank stock and other (non-financial) stock indexes, but also consider government bonds, currencies and residential real estate. Using monthly asset index returns in both local currencies and U.S. dollars, monthly U.S. T-bill yield, crisis starting months and economic data across 44 developed and emerging market countries during 1960 through 2018, they find that: Keep Reading