How to track insider buying without paying for a terminal

Start at the source

SEC EDGAR publishes every filing, with full-text search and per-company filing histories. You can browse a company’s Form 4 filings directly, and you can subscribe to EDGAR’s RSS feeds for new filings.

This is the authoritative copy. Every aggregator, including us, is downstream of it.

Filter to the transactions that reflect a choice

Most Form 4 rows are compensation mechanics: grants, vesting, option exercises, and share withholding for taxes. They are real, but they are not a decision to buy at today’s price.

Filtering to open-market purchases (code P) and open-market sales (code S) removes most of the noise. Checking the Rule 10b5-1 box tells you whether a sale was scheduled in advance.

Read the size against the position

A $40,000 purchase means something different for a director with a $300,000 position than for a founder holding nine figures. The Form 4 reports shares owned following the transaction, which gives you the denominator.

Clusters matter more than single events: several different insiders at the same issuer buying within a short window is a more distinctive pattern than one person adding shares.

Where the manual approach stops working

Doing this for one company is a five-minute task. Doing it across twenty tickers, every day, is not — the filings arrive continuously, and the important ones do not announce themselves.

That is the point where people either accept that they will miss things or set up a standing filter that watches for them.

A note on what the data can and cannot do

Insider transaction data is a record of what happened, not a prediction of what will. Insiders sell for reasons unrelated to their view of the business — diversification, taxes, a house. Treat the filings as facts to investigate, and verify everything against the primary document.