How to track insider selling (SEC filings, 2026)
To learn how to track insider selling, you need two SEC records and the discipline to read them without over-reading them. Insider sales show up on Form 4, filed within two business days of the trade, and are previewed on Form 144 when an affiliate plans a large sale under Rule 144. Both are public on SEC EDGAR. The harder part is interpretation, because insiders sell for many reasons that have nothing to do with the company's prospects. This guide covers how to track insider selling carefully, and it is not investment advice.
Definition
Tracking insider selling
means reading two SEC records: the Form 4, which reports a completed insider trade within two business days, and the Form 144, which is an affiliate's notice before a large Rule 144 sale. Both are public on SEC EDGAR. Sales carry less signal than buys because insiders sell for many reasons. Source: SEC.
Where insider selling is recorded
Two filings do the work:
- Form 4. Officers, directors, and holders of more than ten percent of a company's stock report each trade in that stock within two business days. This is the fastest, most current record of an insider sale.
- Form 144. When an affiliate plans to sell restricted or control stock above the reporting threshold, they file this notice with the SEC before the sale.
2 business days
Deadline for an insider to report a completed sale on Form 4 after the transaction
Source: SEC, Section 16 of the Securities Exchange Act
How to read an insider sale without over-reading it
Treat each filing as a fact, then weigh it. A few practical checks:
- Read the transaction code. An open-market sale is different from an option exercise or a gift. The code tells you the nature of the disposal.
- Check the Rule 10b5-1 box. If the sale ran off a Rule 10b5-1 plan, the timing was set months earlier, so it is a weaker signal than a sudden discretionary sale.
- Size the trade against the holding. A sale that trims a small slice of a large stake means something different from one that clears most of it.
- Read the pattern, not one trade. Several dated filings tell you more than a single line.
Why selling is a weaker signal than buying
The reason to be careful is simple: there is usually one reason to buy your own company's stock and many reasons to sell it. Diversification, taxes, a house, a divorce, or a pre-set plan can all drive a sale. That asymmetry is why disciplined readers treat selling as context rather than a verdict. Buying, which tends to be more deliberate, is covered in how to track insider buying.
For the filings themselves, see what a Form 4 filing is and what a Form 144 filing is, and to hold the plan and the notice apart, read Rule 10b5-1 plan vs Form 144.
Flock reads these filings, keeps each one dated, and links back to its SEC source. What the data means for you is your call to make.
Frequently asked questions
Where can I see insider selling?
Insider sales are reported on SEC Form 4, filed within two business days of the trade, and are previewed on Form 144 when an affiliate plans a large Rule 144 sale. Both are public on SEC EDGAR, so any figure can be checked at the primary source. Source: SEC EDGAR.
How do I know if an insider sale was pre-planned?
Check the Rule 10b5-1 checkbox on the Form 4. If it is ticked, the sale ran off a plan the insider set up in advance, which usually means the timing was not a reaction to recent news. A discretionary sale has that box unchecked. Source: SEC.
Is insider selling a reliable signal?
Selling is generally a weaker signal than buying because insiders sell for many reasons unrelated to the company's outlook, such as diversification, taxes, or a pre-set plan. It is a fact to note, not a recommendation. Source: SEC.
What does the transaction code on a Form 4 mean?
Each Form 4 line carries a code for the transaction type. An open-market sale, an option exercise, and a gift are different codes, so reading the code tells you the nature of the disposal rather than assuming every sale is the same. Source: SEC.
Flock tracks these filings, sourced, dated, and linked back to the original. See what smart-money entities disclosed, without the guesswork about what it means.
Disclosures shown are public regulatory filings. Data may be delayed or incomplete. Smart-money entities may no longer hold positions shown. Not investment advice.