What is an insider's open-market purchase?

The short answer

An open-market purchase is when an insider buys shares of their own company on the stock market, with their own money, at the market price.

Official source: Form 4, General Instruction 8: the transaction codes.

What counts

It is code P on a Form 4. The insider chose to spend cash, on a day of their own choosing, at whatever price the market offered.

What does not count

Stock awards and grants that the company gives
Shares received by exercising options
Shares bought through a company savings or stock-purchase plan
Shares kept back to pay taxes

Why it gets attention

Insiders sell for many reasons, some of them unrelated to the company. They buy with their own money far less often, so a purchase is rarer. A filing shows what happened, never why.

What it does not tell you

A purchase is a person's decision on a given day. It does not say where the stock will go. OQRO measures what happened after each purchase against the S&P 500, and publishes it, including the many that finished behind the market.

A real example

Universal Technical Institute, Form 4 filed 30 September 2026 by Robert T. DeVincenzi, a director, for a purchase on 28 September 2026.

One row in Table I: common stock, code P, 1,000 shares acquired (A) at a price of $19.6775, held directly, with 153,330 shares owned afterwards.
The footnote says the price is a weighted average of purchases made at prices from $19.505 to $19.85.
The Rule 10b5-1 box is not ticked. The form lists his role as director, not officer and not 10% owner.
1,000 shares at $19.6775 is $19,677.50 (simple multiplication of two figures on the form).

This is what a plain open-market purchase looks like on the form: one P row, a price, and no plan. The form shows the size and the date. It does not show the reason, and one purchase of this size is a single data point rather than a pattern.

The record: Universal Technical Institute Form 4, accession 0001193125-26-409200 (filing index on sec.gov) (opened October 8, 2026)

Common mistakes

Counting any acquisition as a purchase. A grant or award is code A, an option exercise is M, and shares received in a gift are G. Only code P is a purchase, and the form's wording is "open market or private purchase", so P alone does not prove the shares were bought on an exchange.
Ignoring who bought. The form states whether the filer is a director, an officer or a 10% owner, and whether the shares are held directly or indirectly.
Reading a price footnote as an error. A weighted-average price with a stated range is the filer's way of reporting several fills at once.
Comparing a purchase of 1,000 shares with one of 100,000 as if size were not on the form. The share count and price are both reported, and the product of the two is the amount.

See it on OQRO

From the blog

Sources

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This explains a public filing in plain words. It is not legal or investment advice.

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