Summary
Updated Aug 31, 2026
Reid Tarlton Campbell is Director of WHITE MOUNTAINS INSURANCE GROUP LTD (WTM). 3 SEC Form 4 filings on record going back to 2025, most recently on 22 May 2026.
Recent Transactions
3Every recent SEC Form 4 transaction Reid Tarlton Campbell has reported, most recent first.
Trading Pattern
InsiderAlpha's records for Reid Tarlton Campbell go back to 2025: 3 primary Form 4 filings, an average of 1.5 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 Reid Tarlton Campbell 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.
- George Manning Rountree - $10.25M of WTM open-market activity in the last 12 months
- Philip A. Gelston - $338K of WTM 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 Reid Tarlton Campbell?
Reid Tarlton Campbell 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 2025, updated as new SEC EDGAR filings are processed.
When did Reid Tarlton Campbell 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 2025.
Has Reid Tarlton Campbell been buying or selling stock?
Recorded transactions: 0 open-market purchases and 1 open-market sale across all tracked filings.
Where can I see all of Reid Tarlton Campbell'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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