SEC Form 4 Explained: How to Read an Insider Filing
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Form 4 is the SEC filing that reports when a company insider buys, sells or otherwise changes their stake in the company's stock. This guide covers what a Form 4 shows, how to read one line by line, what each transaction code means, and how Insider Hawk turns raw filings into the trades you see on the dashboard.
What is SEC Form 4?
Under Section 16 of the Securities Exchange Act, a company's officers, directors and owners of more than 10% of its stock must report changes in their holdings. Most transactions must be reported on Form 4 within two business days. Every filing is public on the SEC's EDGAR system, usually within minutes of submission.
Form 3 vs Form 4 vs Form 5
| Form | What it reports | Deadline |
|---|---|---|
| Form 3 | An insider's initial holdings | Within 10 days of becoming an insider |
| Form 4 | Changes in holdings (buys, sales, grants, exercises) | Within 2 business days of most transactions |
| Form 5 | Annual catch-up for certain exempt or deferred transactions | Within 45 days after the company's fiscal year end |
For tracking insider trading, Form 4 is the one that matters. It is filed quickly and covers open-market buys and sales.
How to read a Form 4
The header names the insider, the company and ticker, and the insider's relationship to the company (Director, Officer with title, 10% Owner, or Other). Since 2023, a checkbox also shows whether the trade was made under a Rule 10b5-1 trading plan.
Table I (non-derivative securities) is where actual stock trades appear. Each row includes:
- Transaction date
- Transaction code (see below)
- Number of shares, and whether they were acquired (A) or disposed of (D)
- Price per share
- Shares owned after the transaction
- Ownership form: direct (D), or indirect (I) through a trust, family member or entity
Table II (derivative securities) covers options, warrants, restricted stock units and convertible securities. Grants and option exercises usually show up here, sometimes alongside a matching line in Table I.
Footnotes often hold the useful context. They may say that the price is a weighted average of several fills (with the price range), that shares are held by a trust or fund, or that the trade was part of a 10b5-1 plan.
Form 4 transaction codes
Every line carries a code. Only P and S reflect an insider deciding to buy or sell shares at a market price. Most other codes are compensation, tax mechanics or transfers.
| Code | Meaning | On Insider Hawk |
|---|---|---|
| P | Open-market or private purchase | Counted as an insider buy |
| S | Open-market or private sale | Counted as an insider sell |
| M | Exercise or conversion of a derivative (exempt under Rule 16b-3) | Shown separately as EXERCISE, not a buy |
| X | Exercise of an in-the-money or at-the-money derivative | Not counted |
| O | Exercise of an out-of-the-money derivative | Not counted |
| C | Conversion of a derivative security | Not counted |
| A | Grant or award from the company | Not counted as a buy |
| D | Disposition to the issuer | Not counted as a sell |
| F | Shares withheld to pay tax or exercise price | Not counted as a sell |
| I | Discretionary transaction under Rule 16b-3(f) | Not counted |
| G | Bona fide gift | Not counted |
| J | Other acquisition or disposition (explained in a footnote) | Not counted |
| W | Acquired or disposed of by will or laws of descent | Not counted |
| L | Small acquisition under Rule 16a-6 | Not counted |
| Z | Deposit into or withdrawal from a voting trust | Not counted |
| K | Equity swap or similar instrument | Not counted |
| E | Expiration of a short derivative position | Not counted |
| H | Expiration or cancellation of a long derivative position | Not counted |
| U | Disposition from a tender of shares in a change of control | Not counted |
| V | Reported voluntarily, earlier than required (added next to another code) | Not a trade type |
The codes people most often misread are A (a grant can look like a big buy), F (tax withholding can look like a sale), and M (an option exercise is not a purchase at market price).
How to find a Form 4 on EDGAR
- Search for the company on SEC EDGAR.
- Filter the filings list by form type "4".
- Open a filing and view the formatted document to see Tables I and II.
Or skip EDGAR: every stock page on Insider Hawk lists that company's insider purchases, newest first.
How Insider Hawk reads Form 4 data
- Filings come straight from SEC EDGAR and are de-duplicated by accession number.
- Only common-stock purchases (code P) and sales (code S) count as buys and sells. Trades under $10,000 are left out.
- Share classes reported in the same filing are combined into one row.
- Amended filings (Form 4/A) replace the lines they correct.
- Sales under a Rule 10b5-1 plan are flagged as planned, since they were scheduled in advance.
- Matched same-day buy and sell pairs in one filing (same shares and price) are excluded as non-trades.
- "% Chg Holdings" compares the shares bought or sold with the shares held before the trade.
What to look for in insider activity
Insiders sell for many ordinary reasons: taxes, diversification, a house. Open-market purchases are rarer and use the insider's own money, so they get more attention. Signals worth watching:
- Cluster buys: two or more insiders buying the same stock within 30 days.
- Size: buys of $1M or more are marked with a whale icon.
- Change in holdings: a buy that meaningfully increases an insider's stake.
- Market-wide trend: the Insider Flow Index compares recent buying and selling with history.
For a deeper look, read How to Interpret Insider Stock Purchases.
Latest insider purchases
In the last 30 days, Insider Hawk recorded 322 insider purchases worth $1.07B across 185 companies.
| Date | Ticker | Insider | Value |
|---|---|---|---|
| Nov 5, '26 | LBTYK | Rodriguez EnriqueEVP, CTO | $2.0M |
| Nov 5, '26 | LBTYK | Fries Michael TPresident & CEO | $1.0M |
| Nov 5, '26 | RRBI | Price Teddy RayDirector | $113K |
| Nov 5, '26 | DGICA | Donegal Mutual Insurance Co10% Owner | $282K |
| Nov 5, '26 | CRH | Talbot SiobhanDirector | $189K |
| Nov 4, '26 | ASPE | Orbimed Advisors LLCDirector | $15.0M |
| Nov 4, '26 | PAM | Zuberbuhler Adolfo FernandoCFO | $207K |
| Nov 4, '26 | CRBG | Nippon Life Insurance Co10% Owner | $6.7M |
Where to go next
- Latest insider buys
- Latest cluster buys
- How to interpret insider stock purchases
- Politician Buys: recent $50K+ stock buys by members of Congress