Summary
Updated Aug 30, 2026
Thomas Sinnickson Gayner is Chief Executive Officer, Director of MARKEL GROUP INC. (MKL). 7 SEC Form 4 filings on record going back to 2024, most recently on 19 May 2026. Most recent open-market trade: bought $155K of MKL on 5 November 2024. Lifetime open-market purchases: $155K.
Recent Transactions
5Every recent SEC Form 4 transaction Thomas Sinnickson Gayner has reported, most recent first.
Other Insiders Active in the Same Stocks
Insiders who reported open-market trades in the last 12 months at the companies Thomas Sinnickson Gayner 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 Quincey - $144.73M of KO open-market activity in the last 12 months
- John Murphy - $27.14M of KO open-market activity in the last 12 months
- Jennifer K. Mann - $25.97M of KO open-market activity in the last 12 months
- Bruno Pietracci - $19.20M of KO open-market activity in the last 12 months
- Nancy Quan - $11.20M of KO open-market activity in the last 12 months
- Manuel Arroyo - $9.89M of KO 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 Thomas Sinnickson Gayner?
Thomas Sinnickson Gayner is a corporate insider, tracked as Chief Executive Officer, Director of MARKEL GROUP INC. (MKL). InsiderAlpha holds 7 primary Form 4 filings for them, the earliest from 2024, updated as new SEC EDGAR filings are processed.
When did Thomas Sinnickson Gayner last file a Form 4?
The most recent primary Form 4 on record is dated 19 May 2026, one of 7 filings going back to 2024.
Has Thomas Sinnickson Gayner been buying or selling stock?
Recorded transactions: 1 open-market purchase ($155K) and 0 open-market sales across all tracked filings.
Where can I see all of Thomas Sinnickson Gayner'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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