Insider conviction intensity
Over the trailing 90 days (anchored on the SEC Form-4 filing date, not the trade date), we count every distinct insider who bought open-market shares. We then compute: log1p(n_distinct_buyers) × log1p(total_dollars_spent) × mean_role_weight — where the role weight per buyer is officers/CEOs 1.0, chairmen 0.9, directors 0.6, an "other" bucket 0.5 (applied when the Form-4 relationship text is unrecognized or blank — it sits between director 0.6 and 10%-owner 0.4), and 10%-owner entities 0.4. Buyers are deduped on filer name, keeping each person's most-senior role, and mean_role_weight is the average across those distinct buyers. Log-scaling gives diminishing returns on both headcount and size; the role weight scales the whole product up when buyers are C-suite rather than passive holders. Result stored in insider_conviction_snapshots.conviction_score.
A high score tells you that multiple insiders — people with line-of-sight to the business — put their own cash in simultaneously and recently. That can sharpen a constructive thesis by adding a "management has skin in the game" data point, or temper skepticism about a weak price chart. It adds nothing to a bearish case and does not override deteriorating fundamentals, since insiders are often early and sometimes wrong.
Scores below ~5 reflect a single small purchase — thin signal, likely noise. The 5–20 band is a modest cluster: a few buyers, mid-size checks. Above 20 the cluster is meaningfully concentrated — several distinct insiders spending real money in a short window. Above ~35 (think 6+ buyers, $100M+, exec-heavy) the pattern is unusually loud by historical norms.
0 (one buyer, no reported dollar value) to roughly 80+ in extreme cases (50+ insiders, $1B+ combined). Typical single-buyer noise: 3–8. Modest cluster: 10–20. Loud cluster: 25–40. Values above 40 are rare and correspond to large, senior, multi-person buying events. No fixed ceiling — both buyer count and dollar size are unbounded in the underlying Form-4 data.
The score ranks loudness within the current 90-day window only — it is explicitly uncalibrated against forward returns. Our own disproof battery found no statistically reliable alpha from insider buying alone, which is why the metric is framed as an intensity index, not a predictive signal.