Investing Research Articles

Prior research suggests that machine learning factor models of the cross section of stock returns greatly enhance portfolio performance by: (1) expanding the dataset to include more variables; and, (2) allowing more complex (non-linear) variable interactions. Does this finding hold up in a realistic portfolio management scenario? In their November 2025 paper entitled “What Drives… Keep Reading

Below is a weekly summary of our research findings for 12/22/25 through 12/26/25. These summaries give you a quick snapshot of our content the past week so that you can quickly decide what’s relevant to your investing needs. Subscribers: To receive these weekly digests via email, click here to sign up for our mailing list.

In response to our inquiry about Goldman Sachs Panic Index data, Grok responded that the data are proprietary and unavailable. However, Grok offered “several high-quality public proxies and near-replicas…built by traders and quants using only freely available data. These reconstructions correlate extremely closely (often 0.90–0.98) with the snippets Goldman has shown clients over the years.”… Keep Reading

Does the New Year’s Day holiday, a time of replanning and income tax positioning, systematically affect investors in a way that translates into U.S. stock market returns? To investigate, we analyze the historical behavior of the S&P 500 Index during the five trading days before and the five trading days after the holiday. Using daily… Keep Reading

Should measures of long-term investment performance incorporate ways in which typical individual investors handle their portfolios over a lifetime rather than an idealized perspective such as buy-and-hold with all distributions reinvested? In his December 2025 paper entitled “Measuring Investor Outcomes”, Hendrik Bessembinder argues that investment performance measures should be realistic and discusses alternative measures of… Keep Reading

How should researchers apply and restrict artificial intelligence (AI) in research? In the December 2025 revision of their editorial entitled “The Use of AI in Academic Research”, Gordon Graham and Jennifer Tucker share experiences as accounting journal editors in dealing with this question. They review the meaning and capabilities of AI. They address the extent… Keep Reading

Below is a weekly summary of our research findings for 12/15/25 through 12/19/25. These summaries give you a quick snapshot of our content the past week so that you can quickly decide what’s relevant to your investing needs. Subscribers: To receive these weekly digests via email, click here to sign up for our mailing list.

Can Grok extract a useful weekly U.S. stock market sentiment metric from posts on X? To investigate, we ask Grok to each week for two years aggregate weekly U.S. stock market sentiment looking for at least 50 posts per week (ending Saturdays) and weighting each post sentiment according to its audience engagement (influence). For example,… Keep Reading

The Inflation Forecast now incorporates actual total and core Consumer Price Index (CPI) data for November 2025. The actual total (core) inflation rate is lower than (lower than) forecasted. Because there were no data for October 2025, we used the forecasted numbers for that month.

How sensitive is performance of the “Simple Asset Class ETF Momentum Strategy” (SACEMS) to choice of momentum calculation lookback interval, and what interval works best? To investigate, we generate gross compound annual growth rates (CAGR) and maximum drawdowns (MaxDD) for SACEMS Top 1, equally weighted (EW) EW Top 2 and EW Top 3 portfolios over lookback… Keep Reading