Corporate insiders (Form 4)

The Insiders page (P600) is the sibling of the Congress board. Members of the House report their trades under the STOCK Act. The officers and directors of a listed US company report theirs to the SEC on Form 4. CAUCUS reads both. This page explains what a Form 4 is, how fast it has to arrive, what research says about insider buying, and where the page's numbers come from.

Who files a Form 4

Section 16(a) of the Securities Exchange Act of 1934 covers three groups at every company with a class of registered stock: its directors, its officers (the president, the principal financial and accounting officers, and any other officer who runs a main business unit or makes policy, which in practice includes the CEO), and anyone who owns more than 10% of a class of its stock. When one of them buys or sells the company's stock, they file a Form 4 that names the stock, the date, the number of shares, the price, and how many shares they hold afterwards.

The Insiders page keeps only officers and directors. A fund that is a 10% owner and nothing else is left out, because it is not running the company.

The two-day rule

Before 2002 a Form 4 was due by the 10th day of the month after the trade, so an insider could wait up to about 40 days. Section 403 of the Sarbanes-Oxley Act of 2002 changed Section 16(a): the form is now due before the end of the second business day after the trade. The SEC set out the rule in Release 34-46421 (August 2002), and the forms have been filed electronically on EDGAR since 2003.

A business day is a day the SEC is open: no weekends, no federal holidays. A trade on Thursday is due by the end of Monday. A Form 4 sent to EDGAR by 10 pm Eastern counts as filed that day (Regulation S-T, Rule 13(a)(4)); the filing date EDGAR shows is the one the page uses.

The page counts, for every buy, the business days from the first trade date in the form to its filing date:

The column chart at the top of the page draws exactly this: one column per buy, a white block for the trade day, one block per business day after it, and a yellow line at the deadline. Late filings happen. Companies have to name late filers in their proxy statement (Item 405 of Regulation S-K); the page shows the count and links the filing.

Which rows count as a buy

Each line in a Form 4 carries a transaction code. The page keeps lines with code P, an open-market or private purchase, in the non-derivative table (shares, not options), marked as acquired. It leaves out everything else, including:

Value is shares times the price per share the insider reported. When a form has several purchase lines, the page adds them up and shows the share-weighted average price. Forms that were later amended (4/A) are skipped so a trade is never counted twice.

Since April 2023 a Form 4 also says whether the trade was made under a Rule 10b5-1 plan, one set up in advance. The dataset records that box as plan.

What research says about insider buying

Academic studies have looked at insider trades for decades. They agree on a few things, each as an average over many trades and many years:

• Purchases carry more information than sales. Insiders sell for many reasons (taxes, a house, diversifying), but buy for one. Lakonishok and Lee, "Are Insider Trades Informative?", Review of Financial Studies 14(1), 2001, pp. 79-111, found the signal mostly in purchases and mostly in smaller companies.
• Jeng, Metrick and Zeckhauser, "Estimating the Returns to Insider Trading: A Performance-Evaluation Perspective", Review of Economics and Statistics 85(2), 2003, pp. 453-471, built a portfolio of insider purchases and found it beat the market on average; a portfolio of insider sales did not.
• Seyhun, "Insiders' Profits, Costs of Trading, and Market Efficiency", Journal of Financial Economics 16(2), 1986, pp. 189-212, found that outsiders copying the public filings kept little of the insiders' edge once trading costs were paid.
• Cohen, Malloy and Pomorski, "Decoding Inside Information", Journal of Finance 67(3), 2012, pp. 1009-1043, separated insiders who trade in the same month every year (routine) from those who do not (opportunistic) and found the information in the opportunistic trades.

None of this is a forecast. The studies cover long periods and thousands of companies; any one buy can go anywhere. CAUCUS shows the filings, it does not say what a stock will do. Nothing here is investment advice.

Where the numbers come from

Everything is read from SEC EDGAR's free public files by web/scripts/insiders_data.py:

1. https://www.sec.gov/files/company_tickers.json gives every listed company's CIK (the SEC's id), roughly largest first.
2. The script takes the first 500 companies there, plus about 200 other large US stocks and every stock House members reported.
3. For each company, https://data.sec.gov/submissions/CIK##########.json lists its recent filings; the script keeps the Form 4s filed in the last 60 days.
4. It reads each Form 4's XML from https://www.sec.gov/Archives/edgar/data/... and keeps the officer and director purchases described above.

The script stays under the SEC's limit of 10 requests a second and sends a User-Agent with a contact address, as the SEC asks. Every row on the page links to the SEC's own rendering of that Form 4. Insiders are named as they sign their filings and shown without photos; the page uses company logos instead.

The "Followable" flag is set for every buy with a ticker. A basket on Solana can follow any listed stock, because the keepers post its official Nasdaq close every day.

An insider basket

Not yet. The Solana program takes STOCK Act report lines today: a member's Bioguide ID, a reported dollar range and the hash of a House Clerk PDF. A basket that follows Form 4 buys needs a second kind of record (the insider's SEC id, the company's CIK, exact shares and price, the accession number) and keepers that read EDGAR. Until that ships and is tested, the insider basket reads "Opens later" and nothing on the page can be put into.

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