Insider Buying & Form 4 Activity
A FilingRadar Editorial guide · 2026-05-16
We are building a live Form 4 activity feed that will appear here. In the meantime, this page covers how to read any Form 4 you encounter on EDGAR, plus four illustrative patterns drawn from historic filings. Read the full Form 4 guide →
What insider activity actually tells you
Form 4 filings disclose insider transactions within 2 business days of execution. Every officer, director, and 10%-or-greater beneficial owner of a US public company files them. The data is free and public on EDGAR — and historically under-used by retail investors relative to its information value.
The signal is not in the volume of filings (executives are constantly receiving option grants and vesting awards). The signal is in the type of transaction. Open-market purchases (P) are the most informative because they are rare and costly to insiders. Our Form 4 guide walks through the full transaction-code taxonomy.
Four insider patterns worth knowing
CEO cluster buy after a 30% drawdown
HIGH3 officers, 4 P-coded purchases within 5 trading days, total $4.2M
High-conviction cluster buying after a price decline is the strongest single insider signal in academic studies. The legal-defense moat plus 6-month Section 16(b) exposure make this hard to fake.
Scheduled 10b5-1 sale during good news
LOWCFO sells 30,000 shares (code S, 10b5-1 box checked) on day of earnings beat
Plan set up months earlier; sale automatic regardless of current performance. Low-information event despite the dollar size.
Discretionary sale before a quiet period
MEDCEO sells 200,000 shares (code S, no 10b5-1 flag) two weeks before the close of fiscal quarter
Non-plan, discretionary sale ahead of a closed-window period. Worth investigating; cross-reference subsequent 8-K filings and the next earnings release.
New director with zero initial holdings
LOWForm 3 filed showing 0 shares for new independent director
Less informative than Form 4 buying, but worth noting — a new director with no skin in the game arrives with different incentives than one who already bought.
Patterns are educational illustrations, not company-specific recommendations. Always verify with the actual SEC filing on EDGAR.
How to find Form 4 filings on EDGAR yourself
- Go to EDGAR's Form 4 latest filings.
- Filter by company using the ticker or CIK number.
- Click any Form 4 to view the transaction. Note the transaction code, share count, price, and whether the 10b5-1 box is checked.
- Cross-reference with the company's recent 10-Q risk factors and any 8-Ks filed in the same window. Patterns matter more than single transactions.
What this guide is not
- Not a recommendation to copy any insider's trades. Insider information value is statistical, not individual.
- Not a substitute for reading the actual Form 4 on EDGAR — the SEC source is always authoritative.
- Not investment advice. See our editorial policy.
Track Form 4 activity for stocks you own
FilingRadar lets you download any company's recent filings — including Form 4s — as clean PDFs. Free, no signup.