Which insider purchases stood out in the week of Sep 28 to Oct 4, 2026?

Information as of 11 October 2026. The figures come from the SEC filings linked below and from OQRO's own count of filings made in that week. If anything here is wrong, tell us at contact@oqro.io and we will correct it.

How were the purchases measured?

OQRO counts every open-market insider purchase reported on an SEC Form 4 and filed between Monday 28 September and Sunday 4 October 2026: 318 purchases worth about $442M, next to 1,139 open-market sales. Each purchase is then compared with every open-market purchase and sale that the same company's insiders filed since 2006, about 1.6 million trades in all. A purchase counts as unusual when it is the first by any insider in years, the largest on record for the company, one of several insiders buying in the same week, or made shortly before the company filed an 8-K. Ten purchases of the 318 met at least one of these tests. The method is described on the methodology page and the full list for each week is on the weekly recap.

Which purchases stood out?

Three of the ten, each checked against the filing it comes from.

Oracle: the largest insider purchase since 2006

Stephen H. Rusckowski, a director of Oracle, bought 25,000 shares on 29 September 2026 at $139.352 a share, about $3.48M, according to his Form 4 filed on 1 October. In OQRO's count of Oracle filings since 2006 it is the largest open-market purchase by any Oracle insider, and the first by one since July 2025. Oracle insiders file many more sales than purchases, which is why a single purchase of this size is easy to see. The company page is on OQRO.

Prothena: a 10% owner buys before an executive leaves

William P. Scully filed as a 10% owner of Prothena. His Form 4 reports a purchase of 162,000 shares at $8.677 on 29 September, about $1.41M, and a second purchase the day before. On 2 October Prothena filed an 8-K under Item 5.02 saying its Chief Development Officer had notified the company that he was resigning, effective 9 October, to take a position with one of its strategic partners. The two filings are three days apart. The 8-K does not mention the purchase, and the Form 4 does not mention the departure.

Group 1 Automotive: the largest purchase on record

Conifer Management, also filing as a 10% owner, reported three purchases of Group 1 Automotive shares on 24 September in a Form 4 filed on 28 September, at prices between $247.26 and $248.85. The largest of the three was 42,495 shares at $247.96, about $10.5M. OQRO counts it as the largest open-market purchase by any Group 1 insider in filings since 2006.

Who files these purchases?

A Form 4 is filed by officers, directors and owners of more than 10% of a company's shares. That is why some of the purchases above come from funds and holding companies rather than from executives: the form names the filer's relationship to the company, and for Prothena and Group 1 Automotive it is "10% owner". A purchase by a 10% owner is still an open-market purchase reported by a person the rules treat as an insider, but it is not a purchase by the company's management, and the two should not be read as the same thing.

What this does not tell you

• Why the buyer bought. A Form 4 shows what was done, the date, the number of shares and the price. It gives no reason.
• Whether the timing means anything. The Prothena purchase and the Prothena 8-K are three days apart. The filings do not say they are connected, and OQRO does not claim they are.
• What happened next. This article describes filings made in one week. It does not measure what the share prices did afterwards.
• The whole market. OQRO covers US-listed companies. Purchases that are not open-market, such as grants and option exercises, are left out of the 318.
• Anything about what to do. It describes the public record. It is not investment advice.

Where to see the full list

The ten purchases, with a link to each filing, are on rare insider trades this week, which refreshes every 30 minutes. The same list is available as an RSS feed and a CSV file, free.