Terrestrial Energy Inc. /DE/ SEC filings IMSR
Terrestrial Energy Inc. /DE/ has 186 filings in SEC EDGAR's recent list, going back to Apr 26, 2024. Its latest annual report, Form ARS, was filed on Apr 29, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 11, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Oct 27, 2026 (other events). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| POS AM | Filing | Nov 3, 2026 | — |
| S-3 | Shelf registration | Nov 3, 2026 | — |
| S-3 | Shelf registration | Nov 3, 2026 | — |
| 4 | Insider transaction | Oct 30, 2026 | Oct 28, 2026 |
| 8-K |
Current report
Other events
|
Oct 27, 2026 | Oct 21, 2026 |
| 4 | Insider transaction | Oct 26, 2026 | Oct 21, 2026 |
| 4 | Insider transaction | Oct 21, 2026 | Oct 19, 2026 |
| 3 | Initial insider ownership | Oct 21, 2026 | Oct 19, 2026 |
| 4 | Insider transaction | Oct 15, 2026 | Oct 14, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 13, 2026 |
| 4 | Insider transaction | Oct 13, 2026 | Oct 9, 2026 |
| 424B3 | Prospectus | Aug 14, 2026 | — |
| 10-Q | Quarterly report | Aug 11, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Aug 11, 2026 | Aug 11, 2026 |
| 4 | Insider transaction | Jul 31, 2026 | Jul 29, 2026 |
| 3 | Initial insider ownership | Jul 31, 2026 | Jul 29, 2026 |
| 8-K |
Current report
Officer or director change
|
Jul 31, 2026 | Jul 27, 2026 |
| 8-K |
Current report
Officer or director change, Regulation FD disclosure
|
Jul 28, 2026 | Jul 23, 2026 |
| 4 | Insider transaction | Jul 27, 2026 | Jul 23, 2026 |
| 3 | Initial insider ownership | Jul 27, 2026 | Jul 23, 2026 |
| 8-K |
Current report
Regulation FD disclosure
|
Jul 21, 2026 | Jul 21, 2026 |
| 8-K |
Current report
Officer or director change
|
Jul 17, 2026 | Jul 14, 2026 |
| 8-K |
Current report
Shareholder vote results
|
Jun 12, 2026 | Jun 11, 2026 |
| EFFECT | Filing | Jun 11, 2026 | — |
| POS AM | Filing | Jun 5, 2026 | — |
| S-8 | Employee stock plan registration | May 19, 2026 | — |
| 424B3 | Prospectus | May 14, 2026 | — |
| 424B3 | Prospectus | May 14, 2026 | — |
| 10-Q | Quarterly report | May 14, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations
|
May 14, 2026 | May 14, 2026 |
| 8-K |
Current report
Officer or director change
|
May 8, 2026 | May 5, 2026 |
| ARS | Annual report to shareholders | Apr 29, 2026 | Dec 31, 2025 |
| DEFA14A | Additional proxy material | Apr 29, 2026 | — |
| DEF 14A | Proxy statement | Apr 29, 2026 | Jun 11, 2026 |
| 8-K |
Current report
Officer or director change
|
Apr 16, 2026 | Apr 16, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 12, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 12, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 12, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 12, 2026 |
| D | Filing | Mar 31, 2026 | — |
| 424B3 | Prospectus | Mar 30, 2026 | — |
| 424B3 | Prospectus | Mar 30, 2026 | — |
| POS EX | Filing | Mar 30, 2026 | — |
| POS EX | Filing | Mar 30, 2026 | — |
| 10-K | Annual report | Mar 30, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Mar 30, 2026 | Mar 30, 2026 |
| 3/A | Filing | Feb 17, 2026 | Oct 29, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 17, 2026 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Jan 29, 2026 | Jan 29, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Jan 22, 2026 | — |
| 3 | Initial insider ownership | Jan 22, 2026 | Oct 29, 2025 |
| 4/A | Amended statement of changes in beneficial ownership of securities | Jan 9, 2026 | Dec 18, 2025 |
| 424B3 | Prospectus | Jan 5, 2026 | — |
| S-8 | Employee stock plan registration | Jan 5, 2026 | — |
| 424B3 | Prospectus | Dec 30, 2025 | — |
| EFFECT | Filing | Dec 23, 2025 | — |
| CORRESP | Letter to the SEC | Dec 23, 2025 | — |
| S-1/A | Amended registration statement | Dec 22, 2025 | — |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 18, 2025 |
| S-1 | Registration statement | Nov 26, 2025 | — |
| 8-K |
Current report
Auditor change
|
Nov 24, 2025 | Nov 21, 2025 |
| 10-Q/A | Amended quarterly report | Nov 21, 2025 | Sep 30, 2025 |
| 10-Q | Quarterly report | Nov 14, 2025 | Sep 30, 2025 |
| 8-K/A | Amended current report | Nov 14, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Nov 13, 2025 | Nov 6, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Nov 12, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Nov 12, 2025 | — |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| 3 | Initial insider ownership | Nov 7, 2025 | Oct 28, 2025 |
| SCHEDULE 13D | Ownership over 5% (active) | Nov 4, 2025 | — |
| SCHEDULE 13D | Ownership over 5% (active) | Nov 4, 2025 | — |
| 8-K |
Current report
Material agreement, Acquisition or sale of assets, Unregistered share sale, Change to shareholder rights, Change in control, Officer or director change, Bylaw or fiscal year change
|
Nov 3, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 30, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 30, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 30, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 30, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 30, 2025 | Oct 28, 2025 |
| 8-K |
Current report
Change to shareholder rights, Bylaw or fiscal year change, Other events
|
Oct 29, 2025 | Oct 23, 2025 |
| 425 | Current report | Oct 22, 2025 | — |
| 8-K |
Current report
Shareholder vote results, Regulation FD disclosure
|
Oct 22, 2025 | Oct 22, 2025 |
| 425 | Form 425 | Oct 2, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Sep 30, 2025 | — |
| 425 | Current report | Sep 29, 2025 | — |
| 8-K |
Current report
Other events
|
Sep 29, 2025 | Sep 29, 2025 |
| EFFECT | Filing | Sep 26, 2025 | — |
| 424B3 | Prospectus | Sep 26, 2025 | — |
| CORRESP | Letter to the SEC | Sep 24, 2025 | — |
| S-4/A | Registration statement | Sep 23, 2025 | — |
| CORRESP | Letter to the SEC | Sep 16, 2025 | — |
| S-4/A | Registration statement | Sep 16, 2025 | — |
| UPLOAD | Letter from the SEC | Sep 12, 2025 | — |
| 425 | Form 425 | Sep 4, 2025 | — |
| S-4/A | Registration statement | Sep 4, 2025 | — |
| CORRESP | Letter to the SEC | Sep 3, 2025 | — |
| UPLOAD | Letter from the SEC | Aug 28, 2025 | — |
| S-4/A | Registration statement | Aug 15, 2025 | — |
| CORRESP | Letter to the SEC | Aug 15, 2025 | — |
| 425 | Form 425 | Aug 15, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 14, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 14, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 14, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 13, 2025 | — |
| 10-Q | Quarterly report | Aug 12, 2025 | Jun 30, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 8, 2025 | — |
| 425 | Form 425 | Aug 6, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 6, 2025 | — |
| UPLOAD | Letter from the SEC | Jul 30, 2025 | — |
| CORRESP | Letter to the SEC | Jul 17, 2025 | — |
| S-4 | Registration for a merger or exchange | Jul 17, 2025 | — |
| 10-Q/A | Amended quarterly report | Jul 17, 2025 | Mar 31, 2025 |
| 10-K/A | Amended annual report | Jul 17, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Restatement
|
Jul 15, 2025 | Jul 15, 2025 |
| UPLOAD | Letter from the SEC | Jun 26, 2025 | — |
| 425 | Form 425 | Jun 24, 2025 | — |
| 425 | Form 425 | Jun 24, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Jun 2, 2025 | — |
| DRS | Filing | May 30, 2025 | — |
| 425 | Form 425 | May 27, 2025 | — |
| 10-Q | Quarterly report | May 20, 2025 | Mar 31, 2025 |
| NT 10-Q | Notification of late filing | May 16, 2025 | Mar 31, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 15, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 14, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 12, 2025 | — |
| 10-K | Annual report | Mar 31, 2025 | Dec 31, 2024 |
| SCHEDULE 13G | Ownership over 5% (passive) | Mar 31, 2025 | — |
| 425 | Form 425 | Mar 28, 2025 | — |
| 425 | Form 425 | Mar 26, 2025 | — |
| DEFA14A | Additional proxy material | Mar 26, 2025 | — |
| 425 | Current report | Mar 26, 2025 | — |
| 8-K |
Current report
Material agreement, Unregistered share sale, Regulation FD disclosure, Other events
|
Mar 26, 2025 | Mar 26, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 21, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 13, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Feb 12, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 11, 2025 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Feb 7, 2025 | — |
| SC 13G | Ownership over 5% (passive) | Nov 14, 2024 | — |
| SC 13G | Ownership over 5% (passive) | Nov 14, 2024 | — |
| SC 13G | Ownership over 5% (passive) | Nov 14, 2024 | — |
| 10-Q | Quarterly report | Nov 13, 2024 | Sep 30, 2024 |
| SC 13G | Ownership over 5% (passive) | Nov 6, 2024 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Oct 17, 2024 | — |
| 8-K |
Current report
Other events
|
Oct 10, 2024 | Oct 10, 2024 |
| 10-Q | Quarterly report | Sep 27, 2024 | Jun 30, 2024 |
| SC 13G | Ownership over 5% (passive) | Aug 26, 2024 | — |
| 8-K |
Current report
Other events
|
Aug 23, 2024 | Aug 23, 2024 |
| 4 | Insider transaction | Aug 20, 2024 | Aug 19, 2024 |
| 4 | Insider transaction | Aug 20, 2024 | Aug 19, 2024 |
| 4 | Insider transaction | Aug 20, 2024 | Aug 19, 2024 |
| 4 | Insider transaction | Aug 20, 2024 | Aug 19, 2024 |
| 8-K |
Current report
Material agreement, Unregistered share sale, Bylaw or fiscal year change, Other events
|
Aug 20, 2024 | Aug 15, 2024 |
| 424B4 | Prospectus | Aug 16, 2024 | — |
| EFFECT | Filing | Aug 15, 2024 | — |
| 3 | Initial insider ownership | Aug 15, 2024 | Aug 15, 2024 |
| 3 | Initial insider ownership | Aug 15, 2024 | Aug 15, 2024 |
| 3 | Initial insider ownership | Aug 15, 2024 | Aug 15, 2024 |
| 3 | Initial insider ownership | Aug 15, 2024 | Aug 15, 2024 |
| 3 | Initial insider ownership | Aug 15, 2024 | Aug 15, 2024 |
| CERT | Filing | Aug 15, 2024 | — |
| 8-A12B | Filing | Aug 15, 2024 | — |
| CORRESP | Letter to the SEC | Aug 13, 2024 | — |
| CORRESP | Letter to the SEC | Aug 13, 2024 | — |
| CORRESP | Letter to the SEC | Aug 2, 2024 | — |
| S-1/A | Amended registration statement | Aug 2, 2024 | — |
| UPLOAD | Letter from the SEC | Jul 31, 2024 | — |
| CORRESP | Letter to the SEC | Jul 19, 2024 | — |
| S-1/A | Amended registration statement | Jul 19, 2024 | — |
| UPLOAD | Letter from the SEC | Jul 10, 2024 | — |
| S-1/A | Amended registration statement | Jul 5, 2024 | — |
| S-1 | Registration statement | Jun 18, 2024 | — |
| UPLOAD | Letter from the SEC | May 24, 2024 | — |
| DRS | Filing | Apr 26, 2024 | — |
Showing 186 filings. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Fabricated Plate Work (Boiler Shops) (SIC 3443)
- Listed as
- IMSR (Nasdaq), IMSRW (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Charlotte, NC
- SEC filer status
- , Emerging growth company
- SEC CIK
- 2019804
- Former names
- HCM II Acquisition Corp. (until Oct 29, 2025)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.