Mathematicians Against Fraudulent Financial and Investment Advice (MAFFIA)
Google data center in Ohio Artificial intelligence s march of progress Without doubt, artificial intelligence (AI) and machine learning (ML) systems have scored numerous remarkable successes over the past few years: Defeating the reigning world chess champion. Defeating two champion contestants on the American quiz show Jeopardy. Defeating the world s best human Go player. Defeating all other…
Life expectancy, 1770-2023; source: Our World in Data Target date funds Target-date funds are currently the rage in the finance world. The term refers to a mutual fund that targets a given retirement date, and then steadily shifts the allocation of assets from, say, a 80%/20% mix of stocks and bonds at the start to, say, a 30%/70% or 20%/80% mix as the target date approaches. Vanguard Group, which…
Morningstar s 2024 year-end report In February 2025, Morningstar released its latest scorecard report of mutual funds, measuring active funds versus index benchmarks as of 31 December 2024. Below is an excerpt of the data from this study. Here success rate is defined by Morningstar as the percentage of actively-managed funds that survive and beat the comparable equal-weighted average passive fund…
History of measurements of the speed of light; from Henrion and Fischloff, Assessing uncertainty in physical constants, American Journal of Physics, September 1986 Reproducibility in modern science Reproducibility has emerged as a major issue in numerous fields of scientific research, ranging from psychology, sociology, economics and finance to biomedicine, scientific computing and physics. Many…
S P500 (black) and QQQ i.e. Nasdaq-100 (orange), 22 Dec 2022 through 23 Dec 2023; courtesy BigCharts Forecasters December 2022 predictions On 20 December 2022, Bloomberg published the results of their annual survey of prominent market forecasters. The consensus: Investors ready to turn the page on the worst year for equities since the global financial crisis should brace for more pain heading into…
Updated 26 July 2025 (c) 2025 Space aliens made this rock Extraterrestrial aliens made this rock While out hiking, I found this rock. The following table gives measurements made on the rock. The first two rows give the overall length and width of the rock. Each of the next six rows, after the first two, gives thickness measurements, made on a 3cm x 6cm grid of points from the top surface. All…
Nasdaq-100 (QQQ) (blue) and S P500 (orange), Jan-June 2023; courtesy BigCharts Mid-March 2023 For a moment, let us turn back the clock to mid-March 2023. Here is a brief summary of the financial news current at the time: The cryptocurrency community was still reeling from the November 2022 collapse of FTX, led by wunderkind Sam Bankman-Fried. The speed of FTX s downfall, transpiring over just a…
A random walk on the base-4 digits of pi (see http://gigapan.com/gigapans/106803) A Random Walk Down Wall Street Fifty years ago, Princeton economics professor Burton Malkiel published A Random Walk Down Wall Street. He boldly asserted that a blindfolded chimpanzee throwing darts could pick a stock portfolio that would do as well as one created by many expert practitioners in the field. At the…
Introduction Suppose, in a national TV newscast, instead of citing data, analysis and predictions from major government agencies, the weatherperson displayed a chart of recent temperatures, noting trends, waves and breakout patterns. Most of us would not have confidence in such a dubious and unorthodox forecast. Or suppose, at a medical clinic, that a cardiologist made some hand measurements of…
A new paper, Causal factor investing: Can factor investing become scientific?, has been written by our esteemed colleague Marcos Lopez de Prado of Cornell University, Abu Dhabi Investment Authority and True Positive Technologies. In his 75-page preprint, Lopez de Prado argues that almost all journal articles in the factor investing literature make assertions that are merely associational…