SEC Form 4 filing activity
Track verified insider purchase activity from SEC filings without the noise.
ClusterSignal reads every Form 4 filing as it reaches SEC EDGAR and reports what was actually filed — no predictions, no recommendations, no investment calls. Just filing activity, in plain language.
Illustrative example — not a real filing
- Director — Form 4, code P4,200 sh @ $18.42
- Chief Financial Officer — Form 4, code P1,000 sh @ $18.61
Filing activity increased: 2 distinct insiders, 6 days apart.
President — Form 4, code P — 800 sh @ $52.10
The filing, in plain language
ClusterSignal doesn't interpret filings for you. It parses them accurately and tells you what was actually reported.
01
What is a Form 4?
Officers, directors, and shareholders who own 10% or more of a public company are required by the SEC to report changes in their stock ownership within two business days. That report is called a Form 4. It's public record, filed with the SEC's EDGAR system, and covers every kind of transaction — purchases, sales, option exercises, gifts, and awards.
02
What is a code-P purchase?
Every transaction on a Form 4 carries a code describing what happened. Code P marks an open-market or privately negotiated purchase — the insider used their own money to acquire shares, rather than receiving an award or exercising options. ClusterSignal filters specifically for code-P transactions, since they're the ones that reflect a discretionary decision to buy.
03
Why filing activity from multiple insiders is worth watching
A single insider purchase is one data point. When two or more distinct insiders at the same company file code-P purchases within a short window, filing activity has increased in a way one purchase alone doesn't show. ClusterSignal surfaces this as multiple insiders filed purchases — a fact about what was filed, not a prediction about what happens next.
Not every code-P purchase is treated the same way. Purchases made under a prearranged Rule 10b5-1 trading plan, under an employee stock purchase plan, or as part of a privately negotiated placement are identified from the filing itself and excluded from cluster detection by default. They remain visible in full filing history — they're just not counted as independent, discretionary buying.
How it works
- 1
Filings are ingested directly from SEC EDGAR
Every new Form 4 is read as it's published, along with amendments — matched back to the filing they correct, not treated as new activity.
- 2
Each purchase is checked against its own filing
Footnotes and disclosed purchase mechanisms determine whether a code-P transaction is a discretionary open-market purchase, or something else — a scheduled plan, an employee purchase program, a negotiated placement.
- 3
A single purchase shows as an insider purchase detected
One insider, one filing, one entry on your watchlist — with the transaction details, not an interpretation of them.
- 4
Multiple insiders in a short window show as filing activity increased
When 2 or more distinct insiders at the same company file code-P purchases within a 14-day window, ClusterSignal surfaces it as multiple insiders filed purchases — each individual transaction, the insiders involved, and the time span, shown separately rather than reduced to one number.
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