Summary
Updated Aug 31, 2026
William N. Mathis is Director of Black Stone Minerals, L.P. (BSM). 3 SEC Form 4 filings on record going back to 2024, most recently on 3 October 2025.
Recent Transactions
3Every recent SEC Form 4 transaction William N. Mathis has reported, most recent first.
Trading Pattern
InsiderAlpha's records for William N. Mathis go back to 2024: 3 primary Form 4 filings, an average of 1.0 per year. 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 N. Mathis 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.
- James Whitehead - $28.10M of BSM open-market activity in the last 12 months
- D. Mark Dewalch - $1.48M of BSM open-market activity in the last 12 months
- Thomas L. Carter Jr. - $1.42M of BSM open-market activity in the last 12 months
- Luke Stevens Putman - $1.31M of BSM open-market activity in the last 12 months
- Ashley J. Longmaid - $150K of BSM 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 N. Mathis?
William N. Mathis is a corporate insider, tracked as Director of Black Stone Minerals, L.P. (BSM). InsiderAlpha holds 3 primary Form 4 filings for them, the earliest from 2024, updated as new SEC EDGAR filings are processed.
When did William N. Mathis last file a Form 4?
The most recent primary Form 4 on record is dated 3 October 2025, one of 3 filings going back to 2024.
Where can I see all of William N. Mathis'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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