What a Form 4 tells you about an insider's trade, and what it does not

A Form 4 is one insider's report of one change in what they own, filed within two business days.

An officer, a director, or anyone who owns more than a tenth of a company's stock is an insider in the SEC's sense, and each time their holding changes they file a Form 4 saying so. The form has to be filed within two business days of the trade. It is public the moment it is filed, it is machine-readable, and it is the only place a reader can see what the people running a company did with its shares, as distinct from what they said about them.

The form is short. It names the person and their relationship to the company, then lists each transaction on a line: the date, a one-letter code for what happened, the number of shares, the price, and how many shares the person owned afterward. A second table does the same for options and units that turn into shares later. Footnotes carry the rest, and the rest is often where the meaning is.

The code says what happened; the price and the counterparty say what kind of thing it was.

Most of the reading is in the code. These are the ones that appear on miners' forms, in the SEC's own words shortened.

Two of these look alike on a share count and are not alike at all. An S is a sale: the insider chose the day, the shares were sold into the market or to a buyer, and cash came back. An F is a withholding: an award vested, the tax on it came due, and the company kept back enough shares to pay it. The insider's count fell in both cases. Only in the first did the insider decide to reduce a holding.

Worked on one filing: an open-market sale.

On 2025-12-05 CleanSpark filed a Form 4 for a director, Amanda Cavaleri. One line: on 2025-12-04, code S, 33,000 shares of common stock at $15.02, 107,289 shares owned afterward. Everything a reader needs is on that line.

The last row is the one the form does not print and the one most worth computing: what fraction of the person's own holding the sale was. The same 33,000 shares would be a small trim for a holder of a million and most of the position for a holder of forty thousand. The count owned afterward is on every line for exactly this purpose.

Worked on another: shares withheld for tax are not a sale.

On 2026-09-09 CleanSpark filed a Form 4 for its chief accounting officer, Brian Carson. It has four lines. On 2026-09-04, code M, restricted stock units of 43,666 and 16,375 settled into shares at a price of zero. On 2026-09-08, code F, 36,836 and then 17,183 shares were withheld at $13.3371 each. The form's checkbox marks the withholding as made under a 10b5-1 plan, which for an award means the timing was set when the award was granted.

Across CleanSpark's insiders for the twelve months to 2026-09-10, that pattern is most of the activity: 104 lines with code M, 40 with code F worth $14.1 million at the stated prices, 21 with code A, and 6 with code S worth $1.9 million. A reader who counted every reduction in an insider's holding as selling would have the picture backwards by a factor of seven.

The awards are the third thing to see. On 2026-03-24 the company filed a Form 4 for its chief executive, S. Matthew Schultz, with two code A lines dated 2026-03-20: 1,816,000 and 480,000 performance stock units. Those are pay, not purchases; they will appear again as code M lines when they settle, and as code F lines when the tax on them is withheld, and the eventual S lines, if any, are the only ones where cash reaches the person from the market.

A 10b5-1 plan fixes the timing in advance, and the form says when one was used.

Rule 10b5-1 lets an insider write down, ahead of time, a schedule or a formula for trades, and then let a broker carry it out on the dates it names. Since the SEC's 2022 amendments there is a waiting period between adopting a plan and its first trade, and the Form 4 has a box that is checked when a trade was made under a plan, with the date the plan was adopted. The point of the plan is that the person is not choosing the day of each sale.

The two largest chief-executive sellers on this site's people pages both traded that way in the twelve months to 2026-09-10. Riot's Jason Les reported five sales under a plan, 387,703 shares for $9.30 million at the stated prices; the latest, filed 2026-06-24, was 62,703 shares at $30.09 with 1,263,556 owned afterward. MARA's Frederick Thiel reported thirteen sales under a plan, 357,565 shares for $4.45 million; the latest, filed 2026-08-19, was 27,505 shares at $9.21 with 4,335,697 owned afterward. In both cases the share of the holding sold in the latest trade was under 5 percent, and in both the day was chosen by a schedule written months earlier.

A sale outside a plan is not wrong and a sale inside one is not innocent; the box simply answers one question, who picked the day, and a reader who ignores it will read a calendar into trades that had none.

Twelve months across the site: what was sold and what was bought.

The people pages add up every code S and every code P line, at the stated prices, for each company over a stated window. Here is the twelve months to 2026-09-10 for the companies with any such line. The sums are this site's arithmetic on the forms; every line behind them is on EDGAR under the links in Sources.

The largest bar needs its footnote before anything else. Of Cipher's $420.5 million, $400.8 million was sold by V3 Holding Ltd and the Bitfury entities that file with it, a ten-percent owner reducing a stake over forty filings; the latest, on 2026-06-04, was 222,422 shares at $26.10 with 58,316,694 still owned. A holder that large is an insider by the SEC's definition and is not management. IREN's bar is two trades: each of the co-chief executives sold 1,000,000 shares, $33.1 million apiece at the stated price. On the buying side, Big Digital Energy's $8.7 million is almost entirely Endeavor Blockchain, LLC, a ten-percent owner, in about sixty purchases; the latest, on 2026-09-02, was 4,000 shares at $6.29.

So the first sort a reader should make is by relationship: a fund unwinding a stake, an executive selling under a plan, and a director buying in the open market are three different events that all print as dollars. The people pages carry the relationship on every line.

What a Form 4 does not say.

It does not say why. The SEC's form has no field for a reason, and a footnote that gives one is the filer's choice. A sale can be tax, a house, a divorce, a plan written a year ago, or a view on the company; the form is the same in every case. It does not say what the person still holds in options or units unless you read the second table and the footnotes. It does not say whether a purchase was an investment or an obligation under an ownership guideline. And it does not say anything at all about the company's next quarter, which is why this site's specification treats insider trades as one input among several, looked at for their timing against announcements, and never as a signal on their own.

The one thing it does say, reliably and within two business days, is what changed and by how much. That is a fact a reader can hold up against a press release dated the same week, and the people pages are built so that the holding-up takes one click.

Read any Form 4 in five steps.

1. Read the relationship line first: officer, director, or ten-percent owner. A fund and a chief financial officer are different readers of the same company.
2. Read the code on each line. Treat only S and P as the person's own decision to sell or buy; M, F and A are an award moving through its stages.
3. Multiply shares by price for S and P lines, and divide the shares by the count owned before the trade for the share of the holding it was.
4. Check the 10b5-1 box and its date. A trade under a plan was timed by a schedule, not by the news of the week it landed in.
5. Put the dates beside the company's announcements in the same window: the ledger and the deal tracker hold them, and the people page of each company lists every form with its line.