What is an insider cluster and why it matters

An insider cluster is 3 or more SEC Form 4 filings from distinct insiders at the same company within a 5-day rolling window. It can show that executives or directors are acting in the same direction at the same time — a pattern that is statistically harder to explain as coincidence than an isolated single trade.

ClusterSignal requires a minimum of 3 distinct insiders and at least $50,000 in aggregate transaction value before flagging a cluster. Trades below individual noise floors ($5K general, $10K VP/Director, $25K CEO/CFO) are excluded before clustering runs.

The closer filings occur in time, the harder it is to explain them as routine portfolio management. Three insiders buying the same stock within a single day scores significantly higher than the same three trading over 30 days.

Seniority carries extra weight. A CEO has a broader, more current view of the business than a director. ClusterSignal scores CEO and CFO participation roughly 3x higher than VP or Director-level trades — 42 and 38 points respectively versus 14 for a VP and 10 for a Director.

BOUGHT clusters (open-market purchases) are often interpreted as insider confidence. SOLD clusters are more nuanced — insiders sell for many reasons including taxes, diversification, or pre-scheduled 10b5-1 plans.

Short Radar is a special designation for sell clusters that clear additional thresholds: $250,000+ aggregate, 3+ sellers, with lower thresholds when C-suite insiders are involved. It flags activity that looks coordinated and out-of-ordinary — not routine diversification.

Each cluster receives a 0-100 score from six factors: insider count, seniority, capital deployed, time velocity, filing speed, and historical win rate. The grade (A/B/C) lets you prioritize quickly. Click any row to open the cluster detail page, where you see the full trades table, price chart, score breakdown, and an AI-generated plain-English analysis.