EXHIBIT 4.1

DESCRIPTION OF SECURITIES OF TERRESTRIAL ENERGY INC. REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

The following summary of the material terms of the capital stock of the Terrestrial Energy Inc. (“we,” “our,” “us,” or the “Company”) is not intended to be a complete summary of the rights and preferences of such securities, and is qualified by reference to our certificate of incorporation, as amended and corrected (the “Certificate of Incorporation”), our bylaws, as amended (the “Bylaws”), the Certificate of Designation of Special Voting Preferred Stock (the “Certificate of Designation”), and the Amended and Restated Warrant Agreement, dated October 28, 2025, by and between the Company and Continental Stock Transfer & Trust Company, as warrant agent (the “Warrant Agreement”), described herein, and certain provisions of Delaware law. We urge you to read each of our Certificate of Incorporation, our Bylaws, the Certificate of Designation, and the Warrant Agreement, described herein, in their entirety for a complete description of the rights and preferences of our securities.

Certain provisions of the Certificate of Incorporation, Bylaws and the Warrant Agreement summarized below may be deemed to have an anti-takeover effect and may delay or prevent a tender offer or takeover attempt that a stockholder might consider in its best interest, including those attempts that might result in a premium over the market price for our common stock.

General

The Certificate of Incorporation authorizes the issuance of 501,000,000 shares, consisting of:

●500,000,000 shares of common stock, par value $0.0001 per share (the “Common Stock”); and

●1,000,000 shares of Preferred Stock, par value $0.0001 per share (the “Preferred Stock”).

Except as otherwise required by the Certificate of Incorporation, the holders of Common Stock shall vote together as a single class (or, if any holders of shares of Preferred Stock are entitled to vote together with the holders of Common Stock, as a single class with such holders of Preferred Stock) on all matters submitted to a vote of stockholders of the Company.

Common Stock

Voting rights. Each holder of record of Common Stock, as such, shall have one vote for each share of Common Stock that is outstanding and held by such holder on all matters on which stockholders are entitled to vote generally. The holders of Common Stock do not have cumulative voting rights.

Dividend rights. Subject to applicable law and the rights, if any, of the holders of any outstanding series of Preferred Stock or any other class or series of stock, in each case having a preference over or the right to participate with the Common Stock with respect to the payment of dividends and other distributions in cash, property or shares of stock of the Company, dividends and other distributions may be declared and paid ratably on the Common Stock out of the assets of the Company that are legally available for this purpose at such times and in such amounts as the Company’s Board of Directors (the “Board”), in its discretion, shall determine.

The payment of future dividends on the Common Stock will depend on the financial condition of the Company, and subject to the discretion of the Board. There can be no guarantee that cash dividends will be declared. The ability of the Company to declare dividends may be limited by the terms and conditions of other financing and other agreements entered into by the Company or any of its subsidiaries from time to time.

Rights upon liquidation, dissolution and winding up. In the event of dissolution, liquidation or winding up of the Company, after payment or provision for payment of the debts and other liabilities of the Company and subject to the rights, if any, of the holders of any outstanding series of Preferred Stock or any class or series of stock having a preference over or the right to participate with the Common Stock with respect to the distribution of assets of the Company upon such dissolution, liquidation or winding up of the Company, the holders of Common Stock shall be entitled to receive the remaining assets of the Company available for distribution to its stockholders ratably in proportion to the number of shares held by them.

Other rights. The holders of Common Stock have no pre-emptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the Common Stock. The rights, preferences and privileges of holders of the Common Stock will be subject to those of the holders of any shares of the Preferred Stock that the Company may issue in the future.

Warrants

Public Warrants

On August 19, 2024, in connection with the Company’s initial public offering, the Company issued warrants to purchase one share of the Company’s Class A ordinary shares, par value $0.0001. Such warrants were exchanged for warrants to purchase a share of Common Stock (the “Public Warrants”) pursuant to the Business Combination Agreement, dated as of March 26, 2025 (as amended from time to time, the “Business Combination Agreement”), by and among the Company, Terrestrial Energy Development Inc., a Delaware corporation (formerly known as Terrestrial Energy Inc., or “TEDI”), and HCM II Merger Sub Inc., a Delaware corporation and a direct wholly owned subsidiary of HCM II (“Merger Sub”). The transactions contemplated by the Business Combination Agreement are referred to herein as the “Business Combination.”

Each Public Warrant will entitle the registered holder to purchase one share of Common Stock at a price of $11.50 per share, subject to adjustment as discussed below, at any time after November 27, 2025, provided that the Company has an effective registration statement under the Securities Act covering the Common Stock issuable upon exercise of such Public Warrants and a current prospectus relating to them is available (or the Company permits holders to exercise such Public Warrants on a cashless basis under the circumstances specified in the Warrant Agreement) and such shares are registered, qualified or exempt from registration under the securities, or blue sky, laws of the state of residence of the holder. Pursuant to the Warrant Agreement, a warrant holder may exercise its Public Warrants only for a whole number of Common Stock. This means only a whole Public Warrants may be exercised at a given time by a warrant holder. No fractional Public Warrants were issued and only whole Public Warrants will trade. The Public Warrants will expire at 5:00 p.m., New York City time, on October 28, 2030, or earlier upon redemption or liquidation.

The Company will not be obligated to deliver any Common Stock pursuant to the exercise of a Public Warrant and will have no obligation to settle such Public Warrant exercise unless a registration statement under the Securities Act with respect to the Common Stock underlying such Public Warrant is then effective and a prospectus relating thereto is current, subject to the Company satisfying its obligations described below with respect to registration. No Public Warrant will be exercisable and the Company will not be obligated to issue a share of Common Stock upon exercise of such Public Warrant unless the Common Stock issuable upon exercise of such Public Warrant has been registered, qualified or deemed to be exempt under the securities laws of the state of residence of the registered holder of such Public Warrant. In the event that the conditions in the two immediately preceding sentences are not satisfied with respect to a Public Warrant, the holder of such Public Warrant will not be entitled to exercise such Public Warrant and such Public Warrant may have no value and expire worthless. In no event will the Company be required to net cash settle any Public Warrant. In the event that a registration statement is not effective for the Common Stock underlying the exercised Public Warrants, the purchaser of a unit in the Company’s initial public offering containing the Public Warrant will have paid the full purchase price for the unit solely for the share of Common Stock underlying such unit.

Under the terms of the Warrant Agreement, the Company has registered the issuance of the shares of Common Stock underlying the Public Warrants on its registration statement on Form S-4 (File No. 333-288735) (the “Registration Statement”). The Company will use its best efforts to maintain a current prospectus relating to the Common Stock issuable upon exercise of the Public Warrants until the expiration of the Public Warrants in accordance with the provisions of the Warrant Agreement. If the Company’s fails to maintain a registration statement covering the Common Stock issuable upon exercise of the Public Warrants, holders may exercise Public Warrants on a “cashless basis” in accordance with Section 3(a)(9) of the Securities Act or another exemption. Notwithstanding the above, if the Common Stock is at the time of any exercise of a Public Warrants not listed on a national securities exchange such that they satisfy the definition of a “covered security” under Section 18(b)(1) of the Securities Act, the Company may, at its option, require holders of Public Warrants who exercise their Public Warrants to do so on a “cashless basis” in accordance with Section 3(a)(9) of the Securities Act and, in the event the Company so elects, the Company will not be required to file or maintain in effect a registration statement, and in the event the Company does not so elect, the Company will use its best efforts to register or qualify the Common Stock under applicable blue sky laws to the extent an exemption is not available. In such event, each holder would pay the exercise price by surrendering the Public Warrants for that number of Common Stock equal to the quotient obtained by dividing (x) the product of the number of Common Stock underlying the Public Warrants, multiplied by the excess of the “fair market value” (defined below) less the exercise price of such Public Warrants by (y) the fair market value. The “fair market value” as used in this paragraph means the volume weighted average price of the Common Stock for the ten (10) trading days ending on the trading day prior to the date on which the notice of exercise is received by the warrant agent.

Redemption of Public Warrants when the price per share of Common Stock equals or exceeds $18.00.

Once the Public Warrants become exercisable, the Company may redeem the outstanding Public Warrants:

●in whole and not in part;

●at a price of $0.01 per Public Warrants; upon a minimum of 30 days’ prior written notice of redemption (the “30-day redemption period”); and

●if, and only if, the closing price of the Common Stock equals or exceeds $18.00 per share (as adjusted for adjustments to the number of shares issuable upon exercise or the exercise price of a Public Warrant as described under the heading “— Anti-dilution Adjustments”) for any twenty (20) trading days within a thirty (30)-trading day period ending three (3) Business Days before the Company sends the notice of redemption to the warrant holders.

If and when the Public Warrants become redeemable by the Company, the Company may exercise its redemption right even if the Company is unable to register or qualify the underlying securities for sale under all applicable state securities laws.

The Company has established the last of the redemption criterion discussed above to prevent a redemption call unless there is at the time of the call a significant premium to the Public Warrant exercise price. If the foregoing conditions are satisfied and the Company issues a notice of redemption of the Public Warrants, each warrant holder will be entitled to exercise his, her or its Public Warrant prior to the scheduled redemption date.

However, the price of the Common Stock may fall below the $18.00 per share redemption trigger price (as adjusted for stock dividends, split-ups, reorganizations, recapitalizations and the like) as well as the $11.50 Public Warrant exercise price after the redemption notice is issued.

Redemption Procedures

A holder of a Public Warrant may notify the Company in writing in the event it elects to be subject to a requirement that such holder will not have the right to exercise such Public Warrant, to the extent that after giving effect to such exercise, such person (together with such person’s affiliates), to the warrant agent’s actual knowledge, would beneficially own in excess of 4.9% or 9.8% (as specified by the holder) of the Common Stock outstanding immediately after giving effect to such exercise.

Anti-dilution Adjustments

If the number of outstanding shares of Common Stock is increased by a stock dividend payable in shares of Common Stock, or by a split-up of Common Stock or other similar event, then, on the effective date of such stock dividend, split-up or similar event, the number of shares of Common Stock issuable on exercise of each Public Warrant will be increased in proportion to such increase in the outstanding shares of Common Stock. A rights offering made to all or substantially all holders of Common Stock entitling holders to purchase shares of Common Stock at a price less than the fair market value will be deemed a stock dividend of a number of shares of Common Stock equal to the product of (i) the number of shares of Common Stock actually sold in such rights offering (or issuable under any other equity securities sold in such rights offering that are convertible into or exercisable for Common Stock) and (ii) the quotient of (x) the price per share of Common Stock paid in such rights offering and (y) the fair market value. For these purposes (i) if the rights offering is for securities convertible into or exercisable for Common Stock, in determining the price payable for shares of Common Stock, there will be taken into account any consideration received for such rights, as well as any additional amount payable upon exercise or conversion and (ii) fair market value means the volume weighted average price of the Common Stock as reported during the ten (10) trading day period ending on the trading day prior to the first date on which the Common Stock trades on the applicable exchange or in the applicable market, regular way, without the right to receive such rights.

In addition, if the Company, at any time while the New Terrestrial Warrants are outstanding and unexpired, pays a dividend or makes a distribution in cash, securities or other assets to all or substantially all the holders of Common Stock on account of such Common Stock (or other securities into which the New Terrestrial Warrants are convertible), other than (a) as described above or (b) certain ordinary cash dividends, then the New Terrestrial Warrant exercise price will be decreased, effective immediately after the effective date of such event, by the amount of cash and/or the fair market value of any securities or other assets paid on each New Terrestrial Common Share in respect of such event.

If the number of outstanding Common Stock is decreased by a consolidation, combination, reverse stock split or reclassification of Common Stock or other similar event, then, on the effective date of such consolidation, combination, reverse stock split, reclassification or similar event, the number of Common Stock issuable on exercise of each Public Warrant will be decreased in proportion to such decrease in outstanding shares of Common Stock.

Whenever the number of shares of Common Stock purchasable upon the exercise of the Public Warrant is adjusted, as described above, the Public Warrant exercise price will be adjusted by multiplying the Public Warrant exercise price immediately prior to such adjustment by a fraction (x) the numerator of which will be the number of shares of Common Stock purchasable upon the exercise of the Public Warrants immediately prior to such adjustment, and (y) the denominator of which will be the number of shares of Common Stock so purchasable immediately thereafter.

In case of any reclassification or reorganization of the outstanding shares of Common Stock (other than those described above or that solely affects the par value of the Common Stock), or in the case of any merger or consolidation of the Company with or into another corporation (other than a consolidation or merger in which the Company is the continuing corporation and that does not result in any reclassification or reorganization of its issued and outstanding shares of Common Stock), or in the case of any sale or conveyance to another corporation or entity of the assets or other property of the Company as an entirety or substantially as an entirety in connection with which the Company is dissolved, the holders of the Public Warrants will thereafter have the right to purchase and receive, upon the basis and upon the terms and conditions specified in the Public Warrants and in lieu of the shares of Common Stock immediately theretofore purchasable and receivable upon the exercise of the rights represented thereby, the kind and amount of stock or other securities or property (including cash) receivable upon such reclassification, reorganization, merger or consolidation, or upon a dissolution following any such sale or transfer, that the holder of the Public Warrants would have received if such holder had exercised their Public Warrants immediately prior to such event. If less than 70% of the consideration receivable by the holders of Common Stock in such a transaction is payable in the form of capital stock or shares in the successor entity that is listed for trading on a national securities exchange or is quoted in an established over-the-counter market, or is to be so listed for trading or quoted immediately following such event, and if the registered holder of the Public Warrant properly exercises the Public Warrant within thirty days following public disclosure of such transaction, the Public Warrant exercise price will be reduced as specified in the Warrant Agreement based on the Black-Scholes Warrant Value (as defined in the Warrant Agreement) of the Public Warrant. The purpose of such exercise price reduction is to provide additional value to holders of the Public Warrants when an extraordinary transaction occurs during the exercise period of the Public Warrants pursuant to which the holders of the Public Warrants otherwise do not receive the full potential value of the Public Warrants.

The Public Warrants are issued in registered form under the Warrant Agreement. The Warrant Agreement provides that the terms of the Public Warrants may be amended without the consent of any holder for the purpose of (i) curing any ambiguity or to correct any defective provision or mistake, (ii) adjusting the provisions relating to cash dividends on ordinary shares as contemplated by and in accordance with the Warrant Agreement or (iii) adding or changing any provisions with respect to matters or questions arising under the Warrant Agreement as the parties to the Warrant Agreement may deem necessary or desirable and that the parties deem to not adversely affect the rights of the registered holders of the Public Warrants, provided that the approval by the holders of at least 50% of the then-outstanding Public Warrants received upon conversion of Public Warrants is required to make any change that adversely affects the interests of the registered holders of such Public Warrants.

The Certificate of Incorporation, the Bylaws and Certain Provisions of Delaware Law

The provisions of the Certificate of Incorporation, the Bylaws and the General Corporation Law of the State of Delaware (the “DGCL”) summarized below may have an anti-takeover effect and may delay, defer or prevent a tender offer or takeover attempt that you might consider in your best interest, including an attempt that might result in your receipt of a premium over the market price for your Common Stock.

The Certificate of Incorporation and Bylaws contain certain provisions that are intended to enhance the likelihood of continuity and stability in the composition of the Board and that may have the effect of delaying, deferring or preventing a future takeover or change in control of us unless such takeover or change in control is approved by such board of directors.

These provisions include:

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Authorized but Unissued Capital Stock. The authorized but unissued Preferred Stock will be available for future issuance without stockholder approval. These additional shares may be utilized for a variety of corporate purposes, including future public offerings to raise additional capital, corporate acquisitions and employee benefit plans. The existence of authorized but unissued Preferred Stock could render more difficult or discourage an attempt to obtain control of a majority of common stock by means of a proxy contest, tender offer, merger or otherwise.

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Director Designees; Classes of Directors. The Board is divided into three classes, designated Class I, Class II and Class III. Each class shall consist, as nearly as may be possible, of one third of the total number of directors constituting the entire Board. The Board is authorized to assign members of the Board already in office to Class I, Class II or Class III at the time such classification becomes effective. Each director shall serve for a term ending on the date of the third annual meeting of stockholders following the annual meeting of stockholders at which such director was elected; provided that each director initially assigned to Class I shall serve for a term expiring at the Company’s 2026 annual meeting of stockholders; each director initially assigned to Class II shall serve for a term expiring at the Company’s 2027 annual meeting of stockholders; and each director initially assigned to Class III shall serve for a term expiring at the Company’s 2028 annual meeting of stockholders; provided further, that the term of each director shall continue until the election and qualification of his or her successor and be subject to his or her earlier death, disqualification, resignation or removal.

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No Cumulative Voting for Directors. The DGCL provides that stockholders are not entitled to cumulate votes in the election of directors unless a corporation’s certificate of incorporation provides otherwise. The Certificate of Incorporation does not provide for cumulative voting. As a result, the holders of Common Stock representing a majority of the voting power of all of the outstanding shares of our capital stock of will be able to elect all of the directors then standing for election.

●	Quorum. The Bylaws provide that at all meetings of the Board, a majority of the Whole Board (as defined therein) will constitute a quorum for the transaction of business.

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Action by Written Consent. Any action required or permitted to be taken by the stockholders of the Company must be effected at a duly called annual or special meeting of such holders and may not be effected by any consent in lieu of a meeting of stockholders by such holders; provided, however, that any action required or permitted to be taken by the holders of Preferred Stock, voting separately as a series or separately as a class with one or more other such series, may be taken without a meeting, without prior notice and without a vote, to the extent expressly so provided by the applicable certificate(s) of designation relating to such series of Preferred Stock.

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Special Meetings of Stockholders. The Certificate of Incorporation provides that, except as otherwise required by law and subject to the rights of the holders of any series of Preferred Stock, special meetings of the stockholders of the Company for any purpose or purposes may be called at any time only by or at the direction of the Chief Executive Officer, the President, or the Chairperson of the Board or by a resolution adopted by the affirmative vote of a majority of the total number of directors at any time in office, or by any person appointed pursuant to such resolution, but such special meetings may not be called by stockholders or any other Person or Persons.

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Advance Notice Procedures. The Bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of the stockholders, and for stockholder nominations of persons for election to the Board to be brought before an annual or special meeting of stockholders. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the Board or by a stockholder who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given the secretary of the Company timely written notice, in proper form, of the stockholder’s intention to bring that business or nomination before the meeting. Although the Bylaws do not give the board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, as applicable, the Bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of the Company.

Limitations on Liability and Indemnification of Officers and Directors

The DGCL authorizes corporations to limit or eliminate the personal liability of directors to corporations and their stockholders for monetary damages for breaches of directors’ fiduciary duties, subject to certain exceptions. The Certificate of Incorporation includes a provision that eliminates the personal liability of directors for monetary damages for any breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted under the DGCL. The effect of these provisions is to eliminate the rights of the Company and its stockholders, through stockholders’ derivative suits on the Company’s behalf, to recover monetary damages from a director for breach of fiduciary duty as a director, including breaches resulting from grossly negligent behavior. However, exculpation does not apply to any director if the director has acted in bad faith, knowingly or intentionally violated the law, authorized illegal dividends or redemptions or derived an improper benefit from his or her actions as a director.

The Bylaws provide that the Company must indemnify and advance expenses to directors and officers to the fullest extent authorized by the DGCL. The Company is also expressly authorized to carry directors’ and officers’ liability insurance providing indemnification for directors, officers and certain employees for some liabilities. The Company believes that these indemnification and advancement provisions and insurance are useful to attract and retain qualified directors and executive officers.

The limitation of liability, indemnification and advancement provisions in the Certificate of Incorporation and the Bylaws may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duty. These provisions also may have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit the Company and its stockholders. In addition, your investment may be adversely affected to the extent the Company pays the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions. The Company believes that these provisions, liability insurance and any indemnity agreements that may be entered into are necessary to attract and retain talented and experienced directors and officers.