The statistics behind investing, worked on real data: averages that mislead, risk measures and their limits, and what backtests can and cannot show.
Each post takes one idea, works it on market data with the arithmetic shown, and states plainly where the method stops working.
Latest in Statistics for Investors
First Post: Monday, November 9, 2026
The first Statistics for Investors post arrives on Monday, November 9, 2026. New posts appear here as they publish.
Guides on the Shelf
Investing 101: From Your First Dollar to Options
The complete beginner-to-advanced investing guide: accounts, stocks, bonds, ETFs, how to read charts, valuation with a worked DCF, options, and futures.
Read the GuideWhy backtests lie
Overfitting and the multiple-comparisons problem: why the strategy that aced its backtest usually fails live, and the checks that expose curve fitting.
Read the GuideThe earnings beat is mostly noise
Why quarterly earnings surprises barely move long-run returns, and the two questions that separate signal from noise in any earnings headline.
Read the GuidePosition sizing without blowing up
Expected value, base rates, and the Kelly fraction: a disciplined framework for deciding how much to risk on any idea, before the idea gets exciting.
Read the GuideVolatility, drawdown, and what "annualized" hides
A single return number conceals the ride you actually take. What volatility and drawdown mean, why annualizing flatters risky strategies, and how to read all three.
Read the GuideCorrelation is not diversification
What lowers portfolio risk, and what only looks like it does. Includes a note on crypto correlation for the blockchain-curious.
Read the GuideWhat the Market Prices Into the Largest US Stocks
October 2026 edition: the implied free cash flow growth inside the prices of the ten largest American companies, measured on one standard set of settings.
Read the GuideGo Deeper
Statistics and Data Analysis for Investing and Trading
The book behind the Monday posts: the statistics investors actually use, with worked examples throughout.
OpenStock Valuation Studio
Free in the browser: a fair value, a buy price, and the full workup for listed companies.
OpenMore Pillars
Valuation
Company valuation with the arithmetic shown: discounted cash flow, multiples, and the assumptions that move the answer.
Browse the PillarSurvey Research and Analysis How-To
How surveys are weighted, adjusted, and read, with step-by-step analysis methods for SPSS, Python, and the browser.
Browse the PillarSmall Area Estimation
Estimates for counties, towns, and other small places, where direct survey numbers run too thin to stand on their own.
Browse the PillarMaine by the Numbers
Maine in data: population, work, housing, and health, county by county, from public sources.
Browse the Pillar