Methodology

Persistfolio uses a deterministic, rules-based quantitative methodology to construct standardized model portfolios from companies in the S&P 500. The process does not rely on predictions, forecasts, or discretionary stock selection. Each company is evaluated using the same predefined methodology.

What Persistfolio Analyzes

For each company, Persistfolio analyzes historical performance relative to the S&P 500 over a fixed analysis horizon, using quantitative and statistical methods designed to identify historically persistent and consistent relative performance rather than short-term performance alone.

Analysis Horizons

Persistfolio evaluates companies independently across four analysis horizons — 3, 5, 10, and 15 years — producing separate model portfolios for each horizon.

Standardized Model Portfolios

Companies that meet Persistfolio's qualification criteria are ranked and used to construct standardized model portfolios of 5, 10, 20, or 30 companies, subject to predefined portfolio-construction and sector-diversification rules.

Persistfolio model portfolios are equal-weighted at construction, with each holding receiving the same initial allocation.

Review and Publication

Model portfolios are reviewed on a predefined schedule. When a company no longer meets the applicable qualification criteria, it may be removed and replaced according to the same rules-based methodology used to construct and maintain the portfolio — not based on discretionary judgment about individual companies.

Prospective Tracking

Once a model portfolio is published, Persistfolio tracks its model performance prospectively against the S&P 500. Portfolio changes are recorded as they occur rather than applied retroactively.

See the Performance page for an explanation of the distinction between historical/hypothetical analysis, prospective model portfolio performance, and actual investor performance.

Proprietary Methodology

Persistfolio provides information about its research framework and methodology at a high level. The specific formulas, statistical thresholds, scoring mechanics, coefficients, and implementation details underlying the methodology are proprietary and are not publicly disclosed.

Historical Leaders

Historical Leaders is a separate, deliberately simple model family, distinct from Persistfolio's methodology above. At each quarterly formation date, it ranks the eligible S&P 500 universe purely by trailing price return over a 3-, 5-, or 10-year lookback, and selects the top 10 or 20 companies by rank, equal-weighted.

Historical Leaders does not use Persistfolio's statistical qualification, persistence scoring, bootstrap inference, WATCH handling, retention rules, or sector diversification constraints. The portfolio is fully reconstructed — not retained and reviewed — at every quarterly formation date.

Our own historical research found that this approach carries substantially higher turnover and can result in much greater sector concentration than Persistfolio. Historical results shown for Historical Leaders use gross price returns and do not include dividends, transaction costs, taxes, or other implementation costs.