When 2+ corporate insiders independently buy their own stock within 14 days, it signals unusual internal conviction — one of the strongest publicly available indicators from SEC Form 4 data.
Quick Answer
A cluster buy signal occurs when two or more corporate insiders independently purchase their company's stock in the open market within a 14-day window. Because each insider acts on their own conviction — spending personal capital, not plan allocations — the convergence of multiple independent buyers is considered one of the strongest signals available from public SEC Form 4 data.
When multiple insiders buy together, it's often a strong signal of internal confidence
| Company | Buyers | Total Value | ConfidenceSignal strength (0–100) from 5 factors: buyers, amount, urgency, C-Suite, and price drop. |
|---|---|---|---|
BEAT HeartBeam, Inc. | 8 insiders 2 C-Suite2 top executives (CEO, CFO, COO, President, or Chairman) buying — strongest insider convictionUrgentInsiders bought within 2 days of each other — unusually concentrated, often precedes major announcementsPost-Drop 37.7%Stock dropped 37.7% in 30 days before insiders bought — they believe the market overreacted | $905K | Very Strong75/100 Score: 75/100
|
ARXS Arxis, Inc. | 7 insiders UrgentInsiders bought within 2 days of each other — unusually concentrated, often precedes major announcements | $5.6M | Strong65/100 Score: 65/100
|
BETR Better Home & Finance Holding Co | 6 insiders 2 C-Suite2 top executives (CEO, CFO, COO, President, or Chairman) buying — strongest insider convictionUrgentInsiders bought within 2 days of each other — unusually concentrated, often precedes major announcements | $2.4M | Strong65/100 Score: 65/100
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See more with free account →InsiderAct ingests Form 4 filings from SEC EDGAR in near real-time. Every open-market purchase (transaction code "P") is extracted and attributed to the reporting insider.
For each company, InsiderAct scans a rolling 14-day window. When two or more distinct insiders make qualifying open-market purchases within that window, a cluster buy event is triggered.
Each cluster is scored by buyer count, C-suite participation, total dollar value, and whether the purchases coincided with a price decline. Higher-confidence clusters rank at the top.
InsiderAct requires at least two distinct corporate insiders making independent open-market purchases (Form 4 transaction code "P") within a 14-day window. The insiders must hold different roles to confirm independence — a CEO and a board director buying together carries more weight than two directors buying simultaneously.
The standard detection window is 14 days. InsiderAct scans a rolling 14-day period for qualifying open-market purchases at the same company. This window is wide enough to capture genuine convergence while tight enough to exclude unrelated individual decisions separated by weeks.
The strength of cluster buying comes from independence. When multiple insiders each decide — separately — to buy their own company's stock with personal funds at roughly the same time, the probability of coincidence drops significantly. Unlike a single insider purchase, a cluster requires multiple independent conviction calls, making it harder to dismiss as routine portfolio management or coincidence.
Academic research on insider trading data (Seyhun, Jeng et al., Cohen et al.) consistently shows cluster insider buying is associated with above-market returns over 3–12 month horizons. However, it is a signal, not a guarantee. Insiders have deep company knowledge but cannot predict macroeconomic shocks, rate changes, or sector-wide dislocations. Cluster signals should anchor further research, not replace it.
No. InsiderAct filters to open-market discretionary purchases only. Automatic 10b5-1 plan transactions are pre-scheduled months in advance and do not reflect real-time conviction. Only Form 4 transaction code "P" (open-market purchase) purchases are included in cluster buy detection.
InsiderAct automatically detects cluster buying events from SEC EDGAR Form 4 filings — no manual scanning required. Free accounts see recent signals; Pro unlocks the full dataset with email alerts.