Summary
Updated Aug 31, 2026
William P. Donnelly is Director of Quanterix Corp (QTRX). 20 SEC Form 4 filings on record going back to 2024, most recently on 19 August 2026. Most recent open-market trade: bought $212K of QTRX on 14 August 2026. Lifetime open-market purchases: $793K.
Recent Transactions
20Every recent SEC Form 4 transaction William P. Donnelly has reported, most recent first.
Trading Pattern
InsiderAlpha's records for William P. Donnelly go back to 2024: 20 primary Form 4 filings, an average of 6.7 per year. The typical open-market purchase is $264K (3 buys totaling $793K). The largest single buy on record is $506K of QTRX in 2025. No transaction on record carries a Rule 10b5-1 flag - the filings look discretionary rather than pre-scheduled, which makes their timing more informative as a signal.
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades in the last 12 months at the companies William P. Donnelly files at. Multiple unrelated insiders buying the same stock within a short window, cluster buying, has historically been one of the strongest Form 4 signals.
- Joshua B. Nelson - $1.12M of TROW open-market activity in the last 12 months
- Robert F. Maclellan - $324K of TROW open-market activity in the last 12 months
- Stephon A. Jackson - $308K of TROW open-market activity in the last 12 months
- Vandana Sriram - $20K of QTRX open-market activity in the last 12 months
- Benjamin Meadows - $10K of QTRX open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
Frequently Asked Questions
Who is William P. Donnelly?
William P. Donnelly is a corporate insider, tracked as Director of Quanterix Corp (QTRX). InsiderAlpha holds 20 primary Form 4 filings for them, the earliest from 2024, updated as new SEC EDGAR filings are processed.
How many SEC Form 4 filings has William P. Donnelly submitted recently?
4 primary Form 4 filings in the last 90 days, covering 2 companies.
Has William P. Donnelly been buying or selling stock?
Recorded transactions: 3 open-market purchases ($793K) and 0 open-market sales across all tracked filings.
Where can I see all of William P. Donnelly's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
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