Do stock screeners actually work?

Short answer: a stock screener reliably does one thing — filter thousands of stocks down to a shortlist by rules you set (momentum, value, growth, technicals). That part works. Whether the shortlist then beats a benchmark like SPY is a separate question, and it’s the one almost no screener answers, because answering it means publishing a dated, benchmarked record of every pick — losers included. So the real question isn’t “do screeners work,” it’s “can this screener prove it” — and you can check that in about five minutes.

Filtering works. Predicting is the unproven part.

Every screener is good at the mechanical job: apply your filters, return the matches. Where tools diverge is the claim stacked on top — that the matches are good stocks. That’s a performance claim, and a performance claim is only worth as much as the evidence behind it. Most screeners offer none you can check: an aggregate “win rate,” a curated set of past winners, or silence. None of those can be falsified, which is the same as saying none of them can be trusted.

How to tell if a stock screener actually works

1. 1

   Look for a per-pick record, not a win-rate number

   A single headline like '72% win rate' with no picks behind it can't be checked. Look for every pick, dated the day it printed — an aggregate figure is a claim, a dated list is evidence.

2. 2

   Check that losers are included and corrections are dated

   A record that shows only winners is marketing. The misses have to be there, recorded the day they printed, never re-ranked or removed, and any correction to a recorded value dated. If the losing picks aren't visible, assume they were dropped.

3. 3

   Confirm every pick is benchmarked

   'Up 40%' means little if SPY was up 45% over the same window. A real record measures each pick against SPY over the same two closes, so you're seeing relative result, not just a rising tide.

4. 4

   Make sure every row is public

   If you can't see every pick, with its date and prices, and re-run the arithmetic yourself, you're taking the screener's word for it. Public rows are what turn a claim into something you can test.

5. 5

   Judge the sample size honestly

   A month of picks in one market regime proves almost nothing. Read how the record is labelled — an honest screener tells you when its sample is too small to be meaningful instead of implying the numbers are a forecast.

Filtering vs. proving it works

The left column is what every screener can do. The right is what it takes to actually prove the picks are worth acting on.

Reflects publicly available information; a specific screener may publish more.

Not investment advice. Scores are descriptive, rules-based information only — not a recommendation to buy or sell, and not indicative of future results.