# EDGAR Filing Document

**Accession Number:** 0002019804
**File Stem:** 9999999995-25-003111
**Filing Date:** 2025-9
**Character Count:** 2133
**Document Hash:** 274c25faf72e4f8c27e3f380d8a1c8f9
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**9999999995-25-003111.hdr.sgml**: 20250929

**ACCESSION NUMBER**: 9999999995-25-003111

**CONFORMED SUBMISSION TYPE**: EFFECT

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250926

**DATE AS OF CHANGE**: 20250929

**EFFECTIVENESS DATE**: 20250926

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** HCM II Acquisition Corp.
- **CENTRAL INDEX KEY:** 0002019804
- **STANDARD INDUSTRIAL CLASSIFICATION:** FABRICATED PLATE WORK (BOILER SHOPS) [3443]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 981785406
- **STATE OF INCORPORATION:** E9
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** EFFECT
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-288735
- **FILM NUMBER:** 251351946

**BUSINESS ADDRESS:**
- **STREET 1:** 100 FIRST STAMFORD PLACE
- **CITY:** STAMFORD
- **STATE:** CT
- **ZIP:** 06902
- **BUSINESS PHONE:** 203-930-2200

**MAIL ADDRESS:**
- **STREET 1:** 100 FIRST STAMFORD PLACE
- **CITY:** STAMFORD
- **STATE:** CT
- **ZIP:** 06902
**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Terrestrial Energy Inc.
- **CENTRAL INDEX KEY:** 0002027582
- **STANDARD INDUSTRIAL CLASSIFICATION:** FABRICATED PLATE WORK (BOILER SHOPS) [3443]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 991587241
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** EFFECT
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-288735-01
- **FILM NUMBER:** 251351947

**BUSINESS ADDRESS:**
- **STREET 1:** 9319 ROBERT D. SNYDER RD.
- **CITY:** CHARLOTTE
- **STATE:** NC
- **ZIP:** 28223
- **BUSINESS PHONE:** 646-687-8212

**MAIL ADDRESS:**
- **STREET 1:** 9319 ROBERT D. SNYDER RD.
- **CITY:** CHARLOTTE
- **STATE:** NC
- **ZIP:** 28223

### UNITED STATES
### SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## Notice of Effectiveness

**Date:** September 26, 2025

**Time:** 16:00:00

**Form Type:** S-4

---

**CIK:** 0002019804

**Company Name:** HCM II Acquisition Corp.

**File Number:** 333-288735

---

**CIK:** 0002027582

**Company Name:** Terrestrial Energy Inc.

**File Number:** 333-288735-01