Summary
Updated Aug 31, 2026
Margaret Dillon is Director of WHITE MOUNTAINS INSURANCE GROUP LTD (WTM). 3 SEC Form 4 filings on record going back to 2024, most recently on 22 May 2026.
Recent Transactions
3Every recent SEC Form 4 transaction Margaret Dillon has reported, most recent first.
Trading Pattern
InsiderAlpha's records for Margaret Dillon 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 Margaret Dillon 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.
- Michael George Rosenbaum - $19.15M of GWRE open-market activity in the last 12 months
- John P. Mullen - $14.11M of GWRE open-market activity in the last 12 months
- George Manning Rountree - $10.25M of WTM open-market activity in the last 12 months
- Jeffrey Elliott Cooper - $6.86M of GWRE open-market activity in the last 12 months
- James Winston King - $4.39M of GWRE open-market activity in the last 12 months
- David Franklin Peterson - $1.26M of GWRE 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 Margaret Dillon?
Margaret Dillon is a corporate insider, tracked as Director of WHITE MOUNTAINS INSURANCE GROUP LTD (WTM). InsiderAlpha holds 3 primary Form 4 filings for them, the earliest from 2024, updated as new SEC EDGAR filings are processed.
When did Margaret Dillon last file a Form 4?
The most recent primary Form 4 on record is dated 22 May 2026, one of 3 filings going back to 2024.
Where can I see all of Margaret Dillon'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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