CLUSTER TAPE

SEC Form 4 · watched continuously

Insiders sell for many reasons. They buy for one.

Cluster Tape monitors every Form 4 filing hitting SEC EDGAR and posts the pattern worth knowing about: several insiders at the same company buying their own stock in the same week. Neutral data, straight from the filings, minutes after they land.

Real-time alerts on your tickers — email, Discord, or Telegram. No spam; one email when it ships.

56,853
Form 4 filings analyzed, Q1 2026
5.0%
contain a real open-market purchase
~24/wk
genuine cluster buys, market-wide
2 min
EDGAR polling cadence

The feed

Three kinds of post. Nothing else.

Every post states what was filed — who, how much, when, sourced to the filing. The feed is free and stays free.

Cluster buy

Several insiders, one company, one week

Three or more separate filings of open-market purchases at the same company within seven days. Rare enough to be news — about two dozen a week across the entire market.

AS FILED · MINUTES AFTER EDGAR

Notable buy

One large purchase, disclosed

A significant open-market buy by an officer, director, or major holder — their own money, on the record within two business days of the trade.

AS FILED · MINUTES AFTER EDGAR

Weekly roundup

The week in insider buying

Every Saturday: the week’s tracked open-market buying in one ranked card — totals, companies, and the filings behind them.

SATURDAYS

Why trust it

Built to not fool you — or itself.

Most “insider buying” noise isn’t conviction, it’s paperwork. The pipeline is engineered around the ways Form 4 data lies:

GRANTS ≠ BUYS
Equity grants, option exercises, and tax withholding are compensation, not conviction. Only open-market purchases count — ever.
10B5-1 EXCLUDED
Pre-arranged trading plans are excluded. A purchase scheduled months ago isn’t a fresh decision.
ONE FILING, ONE DECISION
A fund filing jointly with its affiliates is one decision, however many names are on the form. Clusters count separate filings, never separate signatures.
AMENDMENTS NEVER DOUBLE-COUNT
An amended filing restates an old one — it never counts as a second buy.
HUMANS CHECK THE OUTLIERS
Filings with implausible numbers — and clusters with no officer or director among the buyers — are held for human review instead of auto-posted.

Coming next

The same signals, on your tickers.

The feed shows the whole market. Paid alerts will watch your list: any cluster buy or notable purchase on tickers you choose, delivered to email, Discord, or Telegram the moment it’s filed — with your own thresholds. Join the waitlist above and you’ll hear when it opens; waitlist members go first.

Join the waitlist ↑  ·  Follow the live feed ↗