If you take every Form 4 for a company and add up the shares that moved in, you get a figure that mixes two categories with almost nothing in common. Separating them is the first thing anyone reading insider data has to do.
What a grant is
A grant is the company giving securities to an employee as part of their pay: restricted shares, performance units, options. It carries a transaction code that marks it as an award. The insider pays nothing. The size is set by a compensation committee, and the timing is set by a compensation calendar — usually the same month every year, often shortly after results.
None of that involves the insider forming a view about anything. A large grant in March tells you the annual awards were made in March.
What an open market purchase is
A purchase is the insider buying shares at a market price with their own money, reported under a different code. It is comparatively rare, comparatively small in size, and it is the only category in which the insider chose both to act and to pay.
That is the whole of what the record says. What such a purchase indicates is not something this site will tell you, because that would be an opinion dressed as data.
The other codes matter too
Two more categories are routinely miscounted:
- Shares withheld for tax. When restricted shares vest, a portion is often withheld to cover the tax bill. The holdings figure goes down. Nobody decided to sell anything.
- Exercises. An option exercise moves value from the derivative table into the ordinary share table. The share line looks like an acquisition; frequently it is followed by a same-day sale that pays for the exercise and the tax, and the net change is small.
What this means for any aggregate
Any statement of the form "insiders bought X this quarter" is only meaningful if it says which codes it counted. On this site, aggregates count open market purchases and open market sales separately from awards, withholdings and exercises, and each aggregate names what went into it.
Where a filing's code is ambiguous or missing, the record is shown as filed and left out of the derived category, rather than being assigned to whichever bucket looks likely.