John Hugh Macdiarmid
Director · Terrestrial Energy Inc. /DE/
- 2025
- Dec 22, 2025
- 1
Summary
Latest filing:
John Hugh Macdiarmid is Director of Terrestrial Energy Inc. /DE/ (IMSR). 1 SEC Form 4 filing on record, dated 22 December 2025.
Trading pattern
InsiderAlpha's records for John Hugh Macdiarmid go back to 2025: 1 primary Form 4 filing, an average of 0.5 per year. No recorded transaction carries a Rule 10b5-1 plan flag. An absent flag does not establish whether a transaction was pre-arranged or discretionary.
Other insiders active in the same stocks
Insiders who reported open-market trades in the last 12 months at the companies John Hugh Macdiarmid 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.
- Frederick W. Buckman - $39K in IMSR purchases and sales in the last 12 months
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Frequently asked questions
Who is John Hugh Macdiarmid?
John Hugh Macdiarmid is a corporate insider, tracked as Director of Terrestrial Energy Inc. /DE/ (IMSR). InsiderAlpha holds 1 primary Form 4 filing for them, the earliest from 2025, updated as new SEC EDGAR filings are processed.
When did John Hugh Macdiarmid last file a Form 4?
The only primary Form 4 on record is dated 22 December 2025.