Proofstock rates US stocks with a transparent, six-factor quantitative model. Every rating on this site is produced by the process described below — no discretionary overrides, no hand-picking. These are research ratings, not investment advice, and not buy or sell signals.
Each stock is scored on six independent factors. Every factor is built from the raw inputs below, drawn from daily prices and quarterly fundamentals.
Whether the stock has been trending up relative to its peers, using medium-term price performance.
How profitable and financially sound the business is — high returns on capital and stable earnings, low leverage.
How cheap the stock is relative to fundamentals — lower multiples and higher cash-flow yields score better.
How fast the business is expanding its top and bottom line over a multi-year window.
The market-capitalization profile of the company, capturing the historical tendency for size to influence returns.
How calm the stock's price has been — lower realized volatility scores better.
For each factor, a stock is measured against its own sector peers — not the whole market. A technology company’s value is judged against other technology companies, an energy company’s against other energy companies. This is expressed as a z-score: how many standard deviations above or below the sector median the stock sits. It keeps the model from simply declaring entire sectors good or bad.
Extreme outliers are capped at three standard deviations, so a single freak data point can’t dominate a stock’s score.
The six factor z-scores are averaged into a single composite z-score for each stock.
Composite z-scores are ranked across the entire universe and converted to a percentile from 0 to 100. A percentile of 90 means the stock’s composite is stronger than 90% of the universe.
The percentile is bucketed into one of five ratings (below).
| Strong Bullish | Percentile ≥ 90 | Requires positive ROE (profitability gate). |
| Bullish | Percentile 70 – 89 | |
| Neutral | Percentile 30 – 69 | |
| Bearish | Percentile 10 – 29 | |
| Strong Bearish | Percentile < 10 |
Across the ~1,240-name universe the distribution runs roughly 100 / 260 / 480 / 240 / 120 from Strong Bullish to Strong Bearish. The Strong Bullish tier is smaller because of the profitability gate.
The growth factor requires at least $100 million in trailing-twelve-month revenue. Very small companies can post enormous percentage growth off a tiny base, which distorts the factor; the floor keeps growth meaningful rather than an artifact of a small denominator.
A stock whose composite would otherwise reach the Strong Bullish tier (percentile ≥ 90) but has non-positive ROE is demoted to Bullish. The highest conviction rating is reserved for companies that are actually profitable.
Every day, the top and bottom of the universe are written to an append-only record and never edited afterward. Each daily snapshot carries a SHA-256 hash that is chained to the previous day’s hash — so the published history can’t be silently rewritten after the fact. This is the “proof” in Proofstock: the track record is verifiable, not just asserted. You can browse the locked snapshots and their hashes on the Track Record page.