Methodology
What the data is, where it comes from, and every judgement call we make on the way from an SEC filing to a row on this site.
What is a Form 4?
Corporate insiders — officers, directors, and anyone owning more than 10% of a company's stock — must tell the SEC whenever they trade their own company's shares. They do that on Form 4, and they must file it within two business days of the transaction.
Each Form 4 has two tables. Table I covers non-derivative securities: the common stock itself. Table II covers derivatives: options, warrants, RSUs and convertible notes. We store and display both, but we keep them clearly apart, because acquiring an option is not the same event as buying a share.
How we classify trades
This is the part most insider-trading sites get wrong, and it is the reason InsiderBid exists.
Every Form 4 line carries a one-letter transaction code, and each code is also marked as an acquisition or a disposal. It is tempting to treat every acquisition as "insider buying" — but most acquisitions are nothing of the kind:
- An A (grant) is the company handing an executive shares as pay. They did not choose to buy and they did not pay anything.
- An M (option exercise) is an executive converting options they were granted years ago. It shows up as an acquisition, but no purchase happened at the market price — and it is very often paired with a same-day sale.
- An F (tax withholding) is shares handed back to the company to cover the tax bill on a vesting award. It is a disposal, but it is not a decision to sell.
Only one code means somebody looked at the market price and decided to spend their own money: P, an open-market purchase. That is what we surface by default, and it is the only thing we colour green.
Concretely, we mark a transaction as an Open-Market Purchase only when all three of these are true: the code is P, the security is non-derivative (Table I), and the acquired/disposed flag is A. A code-P row on Table II is a purchase of options, and we label it "Derivative Purchase" instead — a different, weaker claim.
Transaction codes
The complete set of codes the SEC defines, and how each one appears on this site. Hover any badge on the site to see its explanation.
| Code | Our label | What the SEC calls it |
|---|---|---|
| P | BuyOpen-Market Purchase | Open market or private purchase of a non-derivative or derivative security |
| S | SellOpen-Market Sale | Open market or private sale of a non-derivative or derivative security |
| A | GrantGrant / Award | Grant, award or other acquisition pursuant to Rule 16b-3(d) |
| M | ExerciseOption Exercise | Exercise or conversion of derivative security exempted pursuant to Rule 16b-3 |
| F | TaxTax Withholding | Payment of exercise price or tax liability by delivering or withholding securities |
| D | To IssuerDisposition to Issuer | Disposition to the issuer of issuer equity securities pursuant to Rule 16b-3(e) |
| G | GiftGift | Bona fide gift |
| C | ConvertConversion | Conversion of derivative security |
| X | ITM ExerciseIn-the-Money Exercise | Exercise of in-the-money or at-the-money derivative security |
| O | OTM ExerciseOut-of-the-Money Exercise | Exercise of out-of-the-money derivative security |
| I | DiscretionaryDiscretionary Transaction | Discretionary transaction in accordance with Rule 16b-3(f) |
| J | OtherOther | Other acquisition or disposition (footnote required) |
| K | SwapEquity Swap | Transaction in equity swap or instrument with similar characteristics |
| L | Small Acq.Small Acquisition | Small acquisition under Rule 16a-6 |
| U | TenderTender of Shares | Disposition pursuant to a tender of shares in a change of control transaction |
| V | Early ReportVoluntary Early Report | Transaction voluntarily reported earlier than required |
| W | InheritInheritance | Acquisition or disposition by will or the laws of descent and distribution |
| Z | TrustVoting Trust | Deposit into or withdrawal from voting trust |
| E | ExpiredShort Position Expired | Expiration of short derivative position |
| H | ExpiredLong Position Expired | Expiration (or cancellation) of long derivative position with value received |
Rule 10b5-1 plans
A Rule 10b5-1 plan is a trading schedule an insider sets up in advance — "sell 5,000 shares on the first trading day of every quarter" — so they can trade without being accused of acting on inside information.
This matters enormously for interpretation. A sale executed under a plan adopted eighteen months ago tells you almost nothing about what the insider thinks today. A discretionary sale decided on Tuesday tells you rather more. So we flag planned trades, and the screener can filter them out entirely.
Detecting them takes two mechanisms, because the data changed underneath:
- Filings from March 2023 onwards (EDGAR release 23.1) carry a machine-readable checkbox. When it is ticked we show Planned and treat it as fact — it is the filer's own assertion.
- Older filings have no such field. The only evidence is prose in the footnotes, so we search them for references to Rule 10b5-1. When we find one we show Planned? with a question mark, because that is our inference, not the filer's statement.
We also check per-transaction footnotes on modern filings, since the checkbox covers a whole filing while a single filing can mix planned and unplanned lines. If a filer ticked nothing and wrote nothing, we say nothing.
Cluster buys
A single insider buying can mean anything — a bonus landed, a new director topped up their qualifying shares. Several insiders independently buying the same stock at the same time is much harder to explain away.
Our definition, applied exactly:
- 3 or more distinct insiders at the same company,
- each making an open-market purchase (code P) of common stock,
- within a rolling 30-day window.
"Rolling" is meant literally. Every purchase date is treated as the end of a candidate window, and we keep the window with the most distinct buyers. A fixed calendar month would miss a cluster that straddles a month boundary, which is precisely when they tend to happen — after an earnings release.
The timeline on each cluster card shows when inside the window each insider bought, and how much. Five insiders buying on one day is often a single shared event; five buying across four weeks is five separate decisions.
Amendments and corrections
Insiders make mistakes, and correct them with a Form 4/A. When we ingest an amendment we find the filing it restates — matching on issuer, reporting period and reporting owner, since the SEC's XML does not include the original accession number — and mark the superseded filing as replaced. Its transactions stop appearing in feeds, totals and cluster calculations.
This means a trade can disappear from the site, or change value, after it was first published. That is not a bug: it is the public record being corrected. Amended rows carry a 4/A badge.
Late filings
Section 16(a) and Rule 16a-3 require an insider to report a transaction before the end of the second business day following it. Our late filings page counts how long they actually took. It is arithmetic on two dates that appear in the filing itself, and it is published as arithmetic — not as a finding that anyone broke a rule.
Exactly what is counted:
- The clock starts at the deemed execution date where the filing reports one, and at the transaction date otherwise. Some broker-executed trades have their deadline measured from the later date, which is why we use it when it is there.
- Where a filing reports several transactions, the clock starts at the earliest of them.
- Business days exclude weekends and US federal holidays. Counting only weekends would report a filing made the day after Thanksgiving as late.
- Amendments (4/A) are excluded entirely. An amendment corrects an earlier filing and is routinely made months afterwards by design, so measuring it against its own transaction date would report the correction as the offence.
What this does not establish is that any rule was broken. Deadlines can run from dates we cannot see, filings can be made on an insider's behalf, and it is the SEC — not this site — that decides what a late filing means. Every row links to the original document on SEC.gov so the two dates can be checked against the source.
Figures cover the filings we hold, which reaches back as far as our archive does rather than across an insider's whole career. A company or insider page showing a clean record is saying that the filings we have were all made inside the deadline.
Data latency and accuracy
We poll the SEC's live filing feed every two minutes, so a filing usually appears here within a few minutes of hitting EDGAR. A separate job re-walks the SEC's daily index files each morning to catch anything the live feed dropped during a filing rush. You can see the current ingestion lag on the status endpoint.
Things worth knowing before you rely on any of this:
- Filing is not trading. Insiders have two business days to file, so the transaction date is often earlier than the date it appeared.
- Prices are sometimes averages. When a trade filled across many prices, filers report a weighted average and explain the range in a footnote. Our value figure uses the reported price.
- Some rows have no price at all. Grants and gifts have no price, and some filers leave the field as a footnote reference. We show an em dash — never $0 — because a zero in a sortable column would be a claim the filing never made.
- Holdings figures are as reported. The "shares held after" figure covers one ownership form (direct or indirect) at a time. Where the arithmetic does not produce a credible prior holding, we leave the percentage change blank rather than guess.
- Joint filings are attributed to one person. When several owners file together — usually an individual plus a related trust — we attribute the transaction to the most identifiable individual rather than duplicating it, which would multiply the dollar value.
All data comes from SEC EDGAR, is in the public domain, and every row on this site links back to the original filing. If a number here disagrees with the filing, the filing is right — please tell us.
Disclaimer
InsiderBid does not provide investment advice. This site republishes public filings for informational purposes only. Nothing on it is a recommendation to buy or sell any security, and insider buying has no guaranteed relationship to future returns. Data may be delayed, incomplete or wrong. Verify against the original filing and speak to a licensed financial professional before making any investment decision. We are not affiliated with, endorsed by, or connected to the U.S. Securities and Exchange Commission.