Stock Screener Methodology and Quality Rules

What this resource does

A screener narrows a research universe; it does not choose investments. Every screen needs an eligible universe, metric definition, effective date, sort direction, missing-data rule, and tie-breaking rule.

ShareKeyX screeners retain excluded and unavailable counts. A company does not receive a zero simply because a metric is missing, and negative or not-meaningful denominators are handled explicitly.

Methodology

1. Freeze the company and security universe with listing status and liquidity context.
2. Define every metric, period, source, adjustment, and freshness limit.
3. Apply eligibility and missing-data rules before ranking.
4. Publish result count, coverage, distribution, outliers, and methodology version.

How to interpret it

A top-ranked company is top only under the selected rules and observation date. Growth, value, momentum, quality, income, and leverage screens answer different questions.

Composite scores can hide trade-offs. Preserve component values and avoid presenting a score as a probability or recommendation.

Limitations and failure modes

• Stale fundamentals can be paired with current prices.
• Outliers and negative denominators can distort rankings.
• Backtests are vulnerable to survivorship and rebalancing assumptions.
• Screen membership does not establish suitability or future performance.

Research workflow

1. Choose a documented screen.
2. Review coverage and exclusions.
3. Open the underlying company evidence.
4. Test risks and counterevidence before forming a view.

Questions and answers