SEC Form S-3 filed by Momentus Inc.

This registration statement of Momentus Inc. contains two prospectuses:

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in one or more prospectus supplements to the base prospectus. The sales agreement prospectus immediately follows the base prospectus. The $7,350,000 of common stock that may be offered, issued and sold under the sales agreement prospectus is included in the $50,000,000 of securities that may be offered, issued and sold by us under the base prospectus. Upon termination of the sales agreement, any portion of the $7,350,000 included in the sales agreement prospectus that is not sold pursuant to the sales agreement will be available for sale in other offerings pursuant to the base prospectus, and if no shares are sold under the sales agreement, the full $50,000,000 of securities may be sold in other offerings pursuant to the base prospectus.

Subject to Completion, Dated September 19, 2025

 

We may, from time to time, offer and sell up to $50,000,000 of any combination of our Class A common stock, par value $0.00001 (the “common stock” or “Common Stock”), preferred stock, par value $0.00001 (the “preferred stock”), debt securities, warrants or units described in this prospectus, either individually or in combination with other securities, at prices and on terms described in one or more supplements to this prospectus. We may also offer common stock or preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock, or debt securities upon the exercise of warrants.

This prospectus provides you with a general description of the securities that we may offer. Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference, before buying any of the securities being offered.

Securities may be sold by us to or through underwriters or dealers, directly to purchasers or through agents designated from time to time. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

Our common stock is listed on The Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “MNTS.” On September 18, 2025, the last reported sale price of our common stock on Nasdaq was $1.19 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on any securities market or other exchange of the specific security covered by such prospectus supplement.

As of the date of this prospectus, the aggregate market value of our outstanding common stock held by non-affiliates is approximately $22.1 million, which is calculated based on 11,547,339 shares of our outstanding common stock held by non-affiliates and a price of $1.91 per share, the closing price of our common stock on August 13, 2025, which is the highest closing price of our common stock on Nasdaq within the prior 60 days of this prospectus. During the prior twelve calendar month period that ends on and includes the date hereof, we have offered and sold no shares of our common stock pursuant to General Instruction I.B.6 to Form S-3.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” beginning on page 13 of this prospectus and contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the other documents that are incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is    , 2025.

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration statement, we may sell from time to time in one or more offerings up to a total dollar amount of $50,000,000 of shares of common stock, preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or as units in combination with other securities as described in this prospectus. Each time we sell any type or series of securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents we have incorporated by reference into this prospectus. To the extent that any statement that we make in a prospectus supplement is inconsistent with statements made in this prospectus, the statements made in this prospectus will be deemed modified or superseded by those made in a prospectus supplement. You should carefully read both this prospectus and the applicable prospectus supplement and any related free writing prospectus, together with the additional information described under “Where You Can Find More Information,” before buying any of the securities being offered.

Neither we, nor any agent, underwriter or dealer has authorized any person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus, any applicable prospectus supplement or any related free writing prospectus prepared by or on behalf of us or to which we have referred you. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus, any applicable supplement to this prospectus or any related free writing prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate, nor does this prospectus, any applicable supplement to this prospectus or any related free writing prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction.

You should not assume that the information contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate on any date subsequent to the date set forth on the front of the document or that any information we have incorporated by reference is correct on any date subsequent to the date of the document incorporated by reference, even though this prospectus, any applicable prospectus supplement or any related free writing prospectus is delivered, or securities are sold, on a later date.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.”

Except as otherwise indicated herein or as the context otherwise requires, references in this prospectus to “Momentus,” “the Company,” “we,” “us,” “our” and similar references refer to Momentus Inc., an entity incorporated under the laws of the State of Delaware, and where appropriate our consolidated subsidiaries.

This prospectus and the information incorporated herein by reference include trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus, any applicable prospectus supplement or any related free writing prospectus are the property of their respective owners.

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks and uncertainties described under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and discussed under the section entitled “Risk Factors” contained in our most recent Annual Report on Form 10-K, as may be updated by subsequent annual, quarterly and other reports that are incorporated by reference into this prospectus in their entirety. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Forward-Looking Statements.”

This prospectus, including the documents that we incorporate by reference herein, contains, and any applicable prospectus supplement or free writing prospectus including the documents we incorporate by reference therein may contain, forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Exchange Act, including statements regarding our future financial condition, business strategy and plans and objectives of management for future operations. Forward-looking statements include all statements that are not historical facts. In some cases, you can identify forward-looking statements by terminology such as “believe,” “will,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “might,” “approximately,” “expect,” “predict,” “could,” “potentially” or the negative of these terms or other similar expressions. Forward-looking statements include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations.

Discussions containing these forward-looking statements may be found, among other places, in the sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in the documents incorporated by reference herein, including our most recent Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K, as well as any amendments thereto.

These statements relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that could cause our actual results, levels of activity, performance or achievement to differ materially from those expressed or implied by these forward-looking statements. We discuss in greater detail, and incorporate by reference into this prospectus in their entirety, many of these risks and uncertainties under the heading “Risk Factors” contained in the applicable prospectus supplement, in any free writing prospectus we may authorize for use in connection with a specific offering, and in the documents incorporated by reference herein. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. We undertake no obligation to revise or publicly release the results of any revision to these forward-looking statements, except as required by law. Given these risks and uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. All forward-looking statements are qualified in their entirety by this cautionary statement.

We will retain broad discretion over the use of the net proceeds from the sale of the securities offered hereby. Except as described in any prospectus supplement or in any related free writing prospectus that we may authorize to be provided to you, we currently intend to use the net proceeds from the sale of the securities offered by us hereunder primarily for working capital and general corporate purposes. We will set forth in the applicable prospectus supplement or free writing prospectus our intended use for the net proceeds received from the sale of any securities sold pursuant to the prospectus supplement or free writing prospectus.

The following is a description of the material terms of our capital stock. This is a summary only and does not purport to be complete. It is subject to and qualified in its entirety by reference to our Second Amended and Restated Articles of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, each of which are incorporated by reference as an exhibit to the registration statement of which this prospectus forms a part. We encourage you to read our Second Amended and Restated Articles of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, and the applicable provisions of the Delaware General Corporation Law (the “DGCL”), for additional information.

Pursuant to the terms of our Second Amended and Restated Certificate of Incorporation, as amended, our authorized capital stock consists of:

As of September 18, 2025, there were 11,635,152 shares of the Common Stock issued and outstanding and 673,408 shares of Preferred Stock outstanding.

Holders of Common Stock are entitled to one vote per share on all matters submitted to a vote of stockholders. The holders of Common Stock will generally vote together as a single class on all matters submitted to a vote of stockholders, unless otherwise required by Delaware law or the Second Amended and Restated Certificate of Incorporation, as amended.

The Second Amended and Restated Certificate of Incorporation, as amended, and the Amended and Restated Bylaws, as amended (collectively, our “Organizational Documents”), established a classified board of directors (the “board”) that is divided into three classes with staggered three-year terms. Only the directors in one class will be subject to election by a plurality of the votes cast at each annual meeting of stockholders, with the directors in the other classes continuing for the remainder of their respective three-year terms. The Second Amended and Restated Certificate of Incorporation does not provide for cumulative voting for the election of directors.

Subject to preferences that may apply to any shares of Preferred Stock outstanding at the time, the holders of Common Stock are entitled to receive dividends out of funds legally available if the board, in its discretion, determines to issue dividends and then only at the times and in the amounts that the board may determine.

We have not paid any cash dividends on the Common Stock to date and do not intend to pay cash dividends in the foreseeable future. The payment of cash dividends in the future will be dependent upon our revenues and earnings, if any, capital requirements, the terms of any outstanding indebtedness and general financial condition. The payment of any cash dividends will be within the discretion of the board at such time. In addition, the board is not currently contemplating and does not anticipate declaring any stock dividends in the foreseeable future.

The holders of the Common Stock are not entitled to preemptive rights and are not subject to conversion (except as noted above), redemption or sinking fund provisions.

If we become subject to a liquidation, dissolution or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of Common Stock and any participating Preferred Stock outstanding at that time, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights of and the payment of liquidation preferences, if any, on any outstanding shares of Preferred Stock.

All of the outstanding shares of Common Stock are fully paid and non-assessable.

Our board is authorized, subject to limitations prescribed by Delaware law, to issue Preferred Stock in one or more series, to establish from time to time the number of shares to be included in each series, and to fix the designation, vesting, powers, preferences, and rights of the shares of each series and any of its qualifications, limitations, or restrictions, in each case without further vote or action by the stockholders. Our board can also increase or decrease the number of shares of any series of Preferred Stock, but not below the number of shares of that series then outstanding, without any further vote or action by the stockholders.

Our board may authorize the issuance of Preferred Stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of Common Stock. The issuance of Preferred Stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring, or preventing a change in control of the Company and may adversely affect the market price of Common Stock and the voting and other rights of the holders of Common Stock.

We filed the Certificate of Designations, which designated 673,408 shares of our preferred stock as “Series A Convertible Preferred Stock”, all of which are issued and outstanding as of April 18, 2025.

With respect to (i) payment of dividends, (ii) distribution of assets, and (iii) all other liquidation, winding up, dissolution, dividend and redemption rights, the Series A Convertible Preferred Stock shall rank pari passu in priority of payment to all Parity Stock (defined below) and senior in priority of payment to all Junior Stock (defined below) in any liquidation, dissolution, winding up or distribution of the Company, and junior to any indebtedness of the Company.

“Junior Stock” means (i) the Common Stock and (ii) any other equity interest of the Company, in each case which by its terms ranks junior to the Series A Convertible Preferred Stock with respect to payment of dividends and/or distribution of assets.

“Parity Stock” means any equity interest of the Company hereinafter created which by its terms ranks pari passu with the Series A Convertible Preferred Stock.

The Series A Convertible Preferred Stock shall participate in any dividends or distributions paid to the holders of Common Stock as if such Series A Convertible Preferred Stock had been converted into Common Stock as of the record date for such dividend or distribution.

The holders of Series A Convertible Preferred Stock are not entitled to vote on any matters presented to the stockholders for their action or consideration, except as required by law or as otherwise provided in the Certificate of Designations.

Holders of Series A Convertible Preferred Stock may convert all of their respective shares of Series A Convertible Preferred Stock into shares of Common Stock at any time, subject to certain ownership limitations set forth in the Certificate of Designations.

The number of shares of Common Stock that each holder of Series A Convertible Preferred Stock will receive upon conversion of such holder’s shares of Series A Convertible Preferred Stock will be equal to the quotient of the stated value of the shares of Series A Convertible Preferred Stock to be converted, which is $20.80 per share divided by the Conversion Price, which is initially $2.08. No fractional shares of Common Stock shall be issued upon the exercise of any conversion right. Any fractional shares of Common Stock that a holder would otherwise be entitled to will be rounded up to the next whole share.

Holders of Series A Convertible Preferred Stock will have rights to certain adjustments for stock dividends, stock splits and other combinations or subdivisions of its outstanding shares of Common Stock.

Some provisions of Delaware law, the Second Amended and Restated Certificate of Incorporation, as amended, and the Amended and Restated Bylaws, as amended, contain provisions that could make the following transactions more difficult: an acquisition of us by means of a tender offer, an acquisition of us by means of a proxy contest or otherwise, or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that provide for payment of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board. We believe that the benefits of the increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweighs the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

We are subject to the provisions of Section 203 of the DGCL regulating corporate takeovers. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date on which the person became an interested stockholder unless:

Generally, a “business combination” includes a merger, asset or stock sale, or other transaction or series of transactions together resulting in a financial benefit to the interested stockholder. An interested stockholder is a person who, together with affiliates and associates, owns or, within three years prior to the determination of interested stockholder status, did own 15% or more of a corporation’s outstanding voting stock. We expect the existence of this provision to have an anti-takeover effect with respect to transactions the board does not approve in advance. We also anticipate that Section 203 may also discourage attempts that might result in a premium over the market price for the shares of common stock held by stockholders.

Provisions of our Organizational Documents could make it more difficult to acquire us by means of a tender offer, a proxy contest or otherwise, or to remove incumbent officers and directors.

Our Second Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws, as amended, provide for certain provisions that may have an anti-takeover effect:

Our Amended and Restated Bylaws, as amended, provide that we will indemnify our directors and officers, and may indemnify our employees and other agents, to the fullest extent permitted by Delaware law.

Delaware law prohibits the Second Amended and Restated Certificate of Incorporation, as amended, from limiting the liability of our directors for the following:

If Delaware law is amended to authorize corporate action further eliminating or limiting the personal liability of a director, then the liability of our directors will be eliminated or limited to the fullest extent permitted by Delaware law, as so amended. The Second Amended and Restated Certificate of Incorporation does not eliminate a director’s duty of care and, in appropriate circumstances, equitable remedies, such as injunctive or other forms of non-monetary relief, remain available under Delaware law. This provision also does not affect a director’s responsibilities under any other laws, such as the federal securities laws or other state or federal laws. Under our Amended and Restated Bylaws, as amended, we can purchase insurance on behalf of any person whom we are required or permitted to indemnify.

In addition to the indemnification required in our Organizational Documents, we have entered into an indemnification agreement with each member of our board and each of our officers. These agreements provide for the indemnification of our directors and officers for certain expenses and liabilities incurred in connection with any action, suit, proceeding or alternative dispute resolution mechanism, or hearing, inquiry or investigation that may lead to the foregoing, to which they are a party or other participant, or are threatened to be made a party or other participant, by reason of the fact that they are or were a director, officer, employee, agent or fiduciary of us, by reason of any action or inaction by them while serving as an officer, director, agent or fiduciary, or by reason of the fact that they were serving at our request as a director, officer, employee, agent or fiduciary of another entity. In the case of an action or proceeding by or in the right of the Company, no indemnification will be provided for any claim where a court determines that the indemnified party is prohibited from receiving indemnification. We believe that these certificate of incorporation and bylaw provisions and indemnification agreements are necessary to attract and retain qualified persons as directors and officers.

The limitation of liability and indemnification provisions in our Organizational Documents may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duties. They may also reduce the likelihood of derivative litigation against directors and officers, even though an action, if successful, might benefit us and our stockholders. Moreover, a stockholder’s investment may be harmed to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions.

The Common Stock and Public Warrants are listed on the Nasdaq Capital Market under the symbols “MNTS” and “MNTSW,” respectively.

The transfer agent and registrar for the Common Stock is Continental Stock Transfer & Trust Company.

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplement and any related free writing prospectus related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

The indenture will not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than a subsidiary of ours) must assume all of our obligations under the indenture or the debt securities, as appropriate.

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company, or DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating such securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer

agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

The following description, together with the additional information we may include in any applicable prospectus supplement and in any related free writing prospectus, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed or will file forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectus, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

We will describe in the applicable prospectus supplement the terms of the series of warrants being offered, including, to the extent applicable:

Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants by delivering the warrant or warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent, if applicable, in immediately available funds, as provided in the applicable prospectus supplement. We will set forth on the reverse side of any warrant certificate and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to any warrant agent in connection with the exercise of the warrant.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Unless we provide otherwise in the applicable prospectus supplement, the warrants and warrant agreements, and any claim, controversy or dispute arising under or related to the warrants or warrant agreements, will be governed by and construed in accordance with the laws of the State of New York.

Each warrant agent, if any, will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

The following description, together with the additional information we may include in any applicable prospectus supplement and related free writing prospectus, summarizes the material terms and provisions of the units that we may offer under this prospectus. We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We will issue each unit so that the holder of the unit is also the holder of each security included in the unit. As a result, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of any unit agent in the applicable prospectus supplement relating to a particular series of units. The summary below and that contained in any prospectus supplement is qualified in its entirety by reference to all of the provisions of the unit agreement and/or unit certificate, and depositary arrangements, if applicable. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the units that we may offer under this prospectus, as well as the complete unit agreement and/or unit certificate, and depositary arrangements, as applicable, that contain the terms of the units.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of unit agreement and/or unit certificate, and depositary arrangements, as applicable, that contain the terms of the particular series of units we are offering, and any supplemental agreements, before the issuance of such units.

We will describe in the applicable prospectus supplement the terms of the series of units being offered, including:

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Global securities will be registered in the name of the depositary or its participants. Consequently, for global securities, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

We may terminate a global security or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Our obligations, as well as the obligations of any applicable trustee or third party employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with its participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the legal holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “—Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

As an indirect holder, an investor’s rights relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only as global securities, an investor should be aware of the following:

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own names, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, a global security will terminate when the following special situations occur:

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and neither we nor any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

We may sell the securities from time to time pursuant to underwritten public offerings, direct sales to the public, “at the market” offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through one or more underwriters or dealers (acting as principal or agent), through agents, or directly to one or more purchasers. We may distribute securities from time to time in one or more transactions:

A prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you) will describe the terms of the offering of the securities, including, to the extent applicable:

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement other than securities covered by any option to purchase additional shares or other option. If a dealer is used in the sale of securities, we, or an underwriter, will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale. To the extent required, we will set forth in the prospectus supplement the name of the dealer and the terms of the transaction. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time. We may use underwriters, dealers or agents with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, dealer or agent, the nature of any such relationship.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities, and we will describe any commissions we will pay the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, the agent will act on a best-efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

We may provide agents, dealers and underwriters with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents, dealers or underwriters may make with respect to these liabilities. Agents, dealers and underwriters or their affiliates may engage in transactions with, or perform services for, us in the ordinary course of business.

All securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate covering or other short-covering transactions involve purchases of the securities, either through exercise of the option to purchase additional shares or in the open market after the distribution is completed, to cover short positions. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time. These transactions may be effected on any exchange or over-the-counter market or otherwise.

Any underwriters, dealers or agents that are qualified market makers on Nasdaq may engage in passive market making transactions in our common stock on Nasdaq in accordance Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

The validity of the securities offered hereby will be passed upon for us by Bradley Arant Boult Cummings LLP. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

The consolidated financial statements of the Company and subsidiaries as of and for the year ended December 31, 2023 and 2024, incorporated by reference in this prospectus, have been audited by Frank, Rimerman + Co. LLP, an independent registered public accounting firm, as stated in their report. Such consolidated financial statements are incorporated by reference in reliance upon the report of such firm given their authority as experts in accounting and auditing.

We are subject to the periodic reporting requirements of the Exchange Act, and we will file periodic reports, proxy statements and other information with the SEC. These periodic reports, proxy statements and other information are available at www.sec.gov. We also maintain a website at www.momentus.space, at which you may access these materials free of charge as soon as reasonably practicable after they are electronically filed with, or furnished to, the SEC. Information contained on or accessible through our website is not a part of this prospectus, and the inclusion of our website address in this prospectus is an inactive textual reference only. We will provide you without charge, upon your oral or written request, with a copy of any or all reports, proxy statements and other documents we file with the SEC, as well as any or all of the documents incorporated by reference in this prospectus or the registration statement (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into such documents). Requests for such copies should be directed to:

Momentus Inc.

Attn: John C. Rood

Chief Executive Officer

3901 N. First Street

San Jose, CA 95134

Telephone: (650) 564-7820

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus.

We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-12584):

All reports and other documents that we file with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act on or after the date of the filing of the registration statement of which this prospectus forms a part and prior to effectiveness of the registration statement, and on or after the date of this prospectus but before the termination of the offering of the securities hereunder will also be considered to be incorporated by reference into this prospectus from the date of the filing of these reports and documents, and will supersede the information herein; provided, however, that all reports, exhibits and other information that we “furnish” to the SEC will not be considered incorporated by reference into this prospectus. We undertake to provide without charge to each person (including any beneficial owner) who receives a copy of this prospectus, upon written or oral request, a copy of all of the preceding documents that are incorporated by reference (other than exhibits, unless the exhibits are specifically incorporated by reference into these documents). You may request a copy of these materials in the manner set forth under the heading “Where You Can Find More Information,” above.

Subject to Completion, Dated September 19, 2025

 

We have entered into a Sales Agreement, dated September 19, 2025, (the “Sales Agreement”), with A.G.P./Alliance Global Partners (“A.G.P.” or the “Sales Agent”) relating to the sale of shares of our Class A common stock, par value $0.00001 per share (“common stock” or “Common Stock”), offered by this prospectus supplement, having an aggregate offering price of up to $7,350,000 from time to time through or to the Sales Agent, acting as sales agent or principal.

Sales of shares of our common stock, if any, under this prospectus supplement will be made in sales deemed to be “at the market offerings” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended (the “Securities Act”). The Sales Agent is not required to sell any specific amount, but will act as sales agent on a commercially reasonable efforts basis consistent with its normal trading and sales practices, on mutually agreed terms between the Sales Agent and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

As sales agent, A.G.P. is entitled to compensation at a fixed commission rate equal to 3.0% of the gross proceeds of each sale of shares of our common stock. In connection with the sale of our shares of common stock on our behalf, the Sales Agent will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of the Sales Agent will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Sales Agent with respect to certain liabilities, including liabilities under the Securities Act and the Securities Exchange Act of 1934, as amended (the “Exchange Act”). See the section titled “Plan of Distribution” beginning on page 33 for additional information regarding the Sales Agent’s compensation.

Our common stock is listed on The Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “MNTS.” On September 18, 2025, the last reported sale price of our common stock on Nasdaq was $1.19 per share.

As of the date of this prospectus, the aggregate market value of our outstanding common stock held by non-affiliates is approximately $22.1 million, which is calculated based on 11,547,339 shares of our outstanding common stock held by non-affiliates and a price of $1.91 per share, the closing price of our common stock on August 13, 2025, which is the highest closing price of our common stock on Nasdaq within the prior 60 days of this prospectus. During the prior twelve calendar month period that ends on and includes the date hereof, we have offered and sold no shares of our common stock pursuant to General Instruction I.B.6 to Form S-3.

Investing in our common stock involves a high degree of risk. Before making an investment decision, please read the information under the heading “Risk Factors” beginning on page S-12 of this prospectus supplement and in the documents incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

A.G.P.

The date of this prospectus is     , 2025

This prospectus supplement and the accompanying base prospectus relates to part of a registration statement on Form S-3 that we have filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process. Under this shelf registration process, we may sell any combination of the securities described in our base prospectus included in the shelf registration statement in one or more offerings up to a total aggregate offering price of $7,350,000. The $7,350,000 of shares of common stock that may be offered, issued and sold under this prospectus supplement included in the $50,000,000 of securities that may be offered, issued and sold by us pursuant to our shelf registration statement. In connection with such offers and when accompanied by the base prospectus included in the registration statement of which this prospectus supplement is a part, this prospectus supplement will be deemed a prospectus supplement to such base prospectus.

This prospectus supplement relates to the offering of our shares of common stock. Before buying any of our shares of common stock that we are offering, we urge you to carefully read this prospectus supplement, together with the information incorporated by reference as described under the headings “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus supplement. These documents contain important information that you should consider when making your investment decision.

This prospectus supplement describes the terms of this offering of our shares of common stock and also adds to and updates information contained in the documents incorporated by reference into this prospectus supplement. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in any document incorporated by reference into this prospectus supplement that was filed with the SEC before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date (for example, a document incorporated by reference into this prospectus supplement) the statement in the document having the later date modifies or supersedes the earlier statement.

You should rely only on the information contained in or incorporated by reference in this prospectus supplement and in any free writing prospectus that we have authorized for use in connection with this offering. We have not, and the Sales Agent has not, authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the Sales Agent is not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the documents incorporated by reference in this prospectus supplement, and in any free writing prospectus that we have authorized for use in connection with this offering, is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should carefully read this prospectus supplement, the documents incorporated by reference in this prospectus supplement, and any free writing prospectus that we have authorized for use in connection with this offering, in their entirety before making an investment decision.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus supplement were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

This prospectus supplement contains and incorporates by reference market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe that these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. Although we are not aware of any misstatements regarding the market and industry data presented in this prospectus and the documents incorporated herein by reference, these estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” in this prospectus and under similar headings in the other documents that are incorporated by reference into this prospectus supplement. Accordingly, investors should not place undue reliance on this information.

Except as otherwise indicated herein or as the context otherwise requires, references in this prospectus to “Momentus,” the “Company,” “we,” “us,” “our” and similar references refer to Momentus Inc., an entity incorporated under the laws of the State of Delaware, and where appropriate our consolidated subsidiaries.

This prospectus supplement, including the documents that we incorporate by reference herein, may contain, forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended (“the Exchange Act”), including statements regarding our future financial condition, business strategy and plans and objectives of management for future operations. Forward-looking statements include all statements that are not historical facts. In some cases, you can identify forward-looking statements by terminology such as “believe,” “will,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “might,” “approximately,” “expect,” “predict,” “could,” “potentially” or the negative of these terms or other similar expressions. Forward-looking statements include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations.

Discussions containing these forward-looking statements may be found, among other places, in the sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in the documents incorporated by reference in this prospectus, including our most recent Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q, as well as any amendments thereto.

These statements relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that could cause our actual results, levels of activity, performance or achievement to differ materially from those expressed or implied by these forward-looking statements. We discuss in greater detail, and incorporate by reference into this prospectus supplement in their entirety, many of these risks and uncertainties under the section entitled “Risk Factors” included in our most recent Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q, as well as any amendments thereto, filed with the SEC, which are incorporated by reference into this prospectus supplement. Additional factors are discussed under the section entitled “Risk Factors” in this prospectus supplement and any free writing prospectus and under similar headings in the other documents that are incorporated by reference into this prospectus supplement. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. New risks and uncertainties arise from time to time, and it is impossible for us to predict these events or how they may affect us. We undertake no obligation to revise or publicly release the results of any revision to these forward-looking statements, except as required by law. Given these risks and uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. All forward-looking statements are qualified in their entirety by this cautionary statement.

Investing in our common stock involves a high degree of risk, and you should be able to bear the complete loss of your investment. You should consider carefully the risks described below and those described under the section captioned “Risk Factors” contained in our Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on April 1, 2025, as amended by Form 10-K/A filed on April 9, 2025 any subsequent Annual Reports on Form 10-K, any subsequent Quarterly Reports on Form 10-Q or Current Reports on Form 8-K, and all other information contained or incorporated by reference into this prospectus supplement and documents incorporated by reference into this prospectus supplement before deciding whether to purchase any of the common stock being offered under this prospectus supplement. If any of the risks actually occur, our business, consolidated financial condition or results of operations could be adversely affected. In such case, the trading price of our common stock could decline and you could lose all or part of your investment. Our actual results could differ materially from those anticipated in the forward-looking statements made throughout this prospectus supplement as a result of different factors, including the risks we face described below. Unless we have indicated otherwise or the context otherwise requires, references in this prospectus or the documents incorporated by reference herein and therein to the “Company,” “Momentus,” “we,” “us” and “our” refer to Momentus Inc.

The financial statements incorporated by reference in this prospectus supplement have been prepared on a going concern basis of accounting which assumes that we will continue as a going concern, and do not reflect any adjustments that might result if the Company is unable to continue as a going concern. The Company’s ability to continue as a going concern is dependent on the Company’s ability to generate revenues and raise capital. To date, the Company has not generated sufficient revenues to provide cash flows that enable the Company to finance its operations internally. In connection with an evaluation conducted by the Company’s management during the preparation of this report, management concluded that there were conditions and events which raised substantial doubt as to the Company’s ability to continue as a going concern within twelve months after the date of the issuance of the financial statements included in this report.

The uncertainty regarding our ability to continue as a going concern could materially adversely affect our share price and our ability to service our indebtedness, raise new capital or enter into commercial transactions. To address these matters, the Company may take actions that materially and adversely affect our business, including significant reductions in research, development, administrative and commercial activities, reduction of our employee base, and ultimately curtailing or ceasing operations, any of which could materially adversely affect our business, financial condition, results of operations and share price. In addition, doubts about our ability to continue as a going concern could impact our relationships with customers, vendors and other third parties and our ability to obtain, maintain or renew contracts with them, or negatively impact our negotiating leverage with such parties, which could have a material adverse effect on our business, financial condition and results of operations. Furthermore, any loss of key personnel, employee attrition or material erosion of employee morale arising out of doubts about our ability to operate as a going concern could have a material adverse effect on our ability to effectively conduct our business and could impair our ability to execute our strategy and implement our business objectives, thereby having a material adverse effect on our business, financial condition and results of operations.

On September 24, 2024, the Company received a letter from the Listing Qualifications Staff of Nasdaq indicating that the Company was subject to delisting for failure to satisfy Nasdaq’s requirements for continued listing set forth in Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Price Requirement”). The Company had also received deficiency letters on May 23, 2024 and August 21, 2024, respectively, from the Staff notifying the Company that the Company had not filed its Form 10-Q for the periods ending March 31, 2024 and June 30, 2024, respectively, as required for continued listing on the Nasdaq under Nasdaq Listing Rule 5250(c)(1) (the “Periodic Reporting Requirement”). Pursuant to Nasdaq Listing Rule 5810(d)(2), the failures to comply with the Periodic Reporting Requirement individually became additional and separate bases for delisting.

On October 15, 2024, the Company filed its Quarterly Reports on Form 10-Q for the quarters ended March 31, 2024 and June 30, 2024, resolving the deficiencies related to the Periodic Reporting Requirement. On October 17, 2024,

the Company received further notice from the Listing Qualifications Department of Nasdaq notifying the Company that it was not in compliance with the requirements of Nasdaq Listing Rule 5550(b) as a result of not having a minimum of $2,500,000 in stockholders’ equity for continued listing as of June 30, 2024, a market value of listed securities of at least $35 million, or net income from continuing operations of $500,000 in the most recently completed fiscal year or in two of the last three most recently completed fiscal years (the “Equity Rule”).

As permitted by Nasdaq rules, the Company timely requested a hearing before a Nasdaq Hearing Panel to appeal Nasdaq’s delisting determination. The Company requested and received a stay of the suspension of trading and delisting of the Common Stock pending the conclusion of the hearing process, which allowed the Common Stock to remain listed on Nasdaq at least until the Panel renders a decision following the hearing. The hearing before the Panel was held on November 14, 2024, at which the Company requested a suspension of delisting pending its return to compliance.

The Company called a special meeting of stockholders on December 2, 2024, to approve a reverse stock split to regain compliance with Nasdaq rules. On December 12, 2024, the Company effected a 1-for-14 reverse stock split, and on December 27, 2024, the Company’s Common Stock closed above the minimum bid price for ten consecutive trading days as required to regain compliance with the Minimum Bid Price Requirement.

On January 13, 2025, the Company received a letter issued by the Panel granting the Company’s request to continue its listing on Nasdaq until April 15, 2025 while the Company executed its plan to regain compliance with the requirements of the Equity Rule.

As disclosed in the Company’s Current Report on Form 8-K filed on April 14, 2025, on April 12, 2025, the Company entered into the Master Services Agreement with VLD, pursuant to which VLD will provide services to design and produce components and systems that will be utilized by the Company or its customers in its spacecraft, systems, and components. In exchange for the services, the Company issued an aggregate of 477,455 shares of Common Stock and 673,408 shares of non-voting Series A Convertible Preferred Stock.

On June 24, 2025, the Company announced that it had received a letter from Nasdaq providing written confirmation that the Company has regained compliance with Nasdaq’s rules. Nasdaq has indicated that if the Company’s stockholder’s equity as of June 30, 2025 included in the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2025 does not show a stockholder’s equity of at least $2,500,000, then the Company may again be subject to delisting from Nasdaq. In the Company’s Quarterly Report for the quarter ended June 30, 2025, filed with the SEC on August 19, 2025, the Company reported a stockholders’ deficit of approximately $9.97 million.

The Master Services Agreement with VLD provided for the cancellation of shares of the Company’s capital stock held by VLD in certain circumstances upon expiration or termination. On August 14, 2025, the Company irrevocably waived its right under the Master Services Agreement to cancel such shares upon expiration or termination of the Master Services Agreement.

The Company believes that, after giving effect to the Master Services Agreement waiver described above, along with the proceeds from the public offering conducted in July 2025 and a warrant inducement transaction consummated in August 2025, the Company’s stockholders’ equity as of August 14, 2025 is in excess of $2.5 million.

There can be no assurance that the Company will be able to maintain compliance with the Equity Rule, the Minimum Bid Price Requirement, the Periodic Reporting Requirement, or other applicable Nasdaq listing rules, that the Company will be able to successfully implement a reverse stock split if it decides to pursue one, that the Panel will grant any future request from the Company for a suspension of delisting on Nasdaq, or that the Company’s appeal of a delisting determination will be successful. Additionally, if we fail to meet the Minimum Bid Price Requirement, we are not eligible for a 180-day cure period from Nasdaq to regain compliance with such requirement because we have conducted a reverse stock split in the past year and thus we would be immediately delisted.

If at the time of filing of the Company’s next periodic financial statements the Company does not evidence compliance with the Equity Rule, the Company may again be subject to delisting from Nasdaq. If the Common Stock loses its listing on the Nasdaq Capital Market, the common stock would likely trade in the over-the-counter market. If the common stock were to trade on the over-the-counter market, selling the common stock could be more difficult because smaller quantities of shares would likely be bought and sold, transactions could be delayed, and security analysts’ coverage of us may be reduced. In addition, in the event the common stock is delisted, broker-dealers have certain regulatory burdens imposed upon them, which may discourage broker-dealers from effecting transactions in the common stock, further limiting the liquidity of such shares. A determination that the common stock is a “penny

stock” would require brokers trading in the common stock to adhere to even more stringent rules and possibly result in a reduced level of trading activity in the secondary trading market for the common stock. These factors could result in lower prices and larger spreads in the bid and ask prices for the common stock. Such delisting from the Nasdaq Capital Market and continued or further declines in the price of shares of the common stock could also greatly impair our ability to raise additional necessary capital through equity or debt financing, and could significantly increase the ownership dilution to stockholders caused by our issuing equity in financing or other transactions.

We intend to use the net proceeds from this offering for general corporate purposes, which may include the development of our orbital transfer and satellite bus vehicles, research and development efforts relating to these vehicles, working capital, capital expenditures, repayment and refinancing of debt, research and development expenditures, acquisitions of additional companies or technologies and investments. From time to time, we engage in preliminary discussions and negotiations with various businesses in order to explore the possibility of an acquisition or investment. However, as of the date of this prospectus, we have not entered into any agreements or arrangements which would make any acquisition, investment, or repayment and refinancing of debt probable.

However, our management will have broad discretion in the application of the net proceeds from this offering and could spend the proceeds in ways that do not improve our results of operations or enhance the value of the common stock. The failure by management to apply these funds effectively could result in financial losses that could have a material adverse effect on our business and cause the price of the common stock to decline.

The issuance of a large number of shares of common stock in an offering at a price that is a discount to the market price of the stock, is likely to result in a decrease in the price of the common stock. Our common stock is currently listed on The Nasdaq Capital Market. Continued listing of a security on The Nasdaq Capital Market is conditioned upon compliance with various continued listing standards. In particular, the requirements for The Nasdaq Capital Market imposes a minimum $1.00 per share bid price requirement. To comply with this requirement, the closing price for our common stock must not fall below $1.00 for a 30 consecutive trading day period. If we are unable to maintain a minimum closing price of $1.00 per share for the 30 consecutive trading days, we will receive a delist letter from the staff of The Nasdaq Stock Market. In addition to The Nasdaq Stock Market enumerated criteria for continued listing on The Nasdaq Capital Market tier, The Nasdaq Stock Market also has broad discretionary public interest authority that it can exercise to apply additional or more stringent criteria for continued listing, or to suspend or delist securities even though the securities meet all enumerated criteria for continued listing on The Nasdaq Stock Market.

Additionally, in the event of a delisting notice, we would typically have an opportunity to appeal such decision to the Nasdaq Hearing Panel or take other measures to preserve the listing of our common stock on The Nasdaq Capital Market, but these measures and any appeal may not be successful. If our common stock is delisted by The Nasdaq Stock Market, our common stock may be eligible to trade on an over-the-counter quotation system, where an investor may find it more difficult to sell our common stock or obtain accurate quotations as to the market value of our common stock. We cannot ensure that our common stock, if delisted from The Nasdaq Capital Market, will be listed on any national securities exchange or quoted on an over-the counter quotation system.

In the event we are delisted from The Nasdaq Capital Market, the only established trading market for our common stock would be eliminated, and we would be forced to list our shares on the OTC Markets or another quotation medium, depending on our ability to meet the specific listing requirements of those quotation systems. As a result, an investor would likely find it more difficult to trade or obtain accurate price quotations for our common stock.

Delisting would likely also reduce the visibility, liquidity, and value of our common stock, reduce institutional investor interest in our company, and may increase the volatility of our common stock. Delisting could also cause a loss of confidence of potential industry partners, lenders, and employees, which could further harm our business and our future prospects.

Unless our common stock is listed on a national securities exchange, such as The Nasdaq Stock Market, our common stock will also likely be subject to the regulations and restrictions regarding trading in “penny stocks,” which are those securities trading for less than $5.00 per share, and that are not otherwise exempted from the definition of a penny stock under other exemptions provided for in the applicable regulations. These penny stock requirements and regulations could severely limit the liquidity of our common stock in the secondary market because fewer brokers or dealers would be likely to be willing to undertake related compliance activities to trade in our common stock. If our common stock is not listed on a national securities exchange, the rules and restrictions regarding penny stock transactions may limit an investor’s ability to sell to a third-party and our trading activity in the secondary market may be reduced. Delisting from The Nasdaq Capital Market would also likely limit the range and attractiveness of strategic alternatives that we are able to consider, adversely affect our ability to raise additional capital through the public or private sale of equity securities, significantly affect the ability of investors to trade our securities, and/or negatively affect the value and liquidity of our common stock.

Sales of a substantial number of shares of the common stock by our existing stockholders in the public market, or the perception that these sales might occur, could depress the market price of the common stock and could impair our ability to raise additional capital through the issuance of additional equity securities. We are unable to predict the effect that such sales may have on the prevailing market price of the common stock.

Any issuance of equity we may undertake in the future to raise additional capital could cause the price of the common stock to decline, or require us to issue shares at a price that is lower than that paid by holders of the common stock in the past, which would result in those newly issued shares being dilutive. In addition, future investors could gain rights superior to existing stockholders, such as liquidation and other preferences. If we obtain funds through a credit facility or through the issuance of debt or preferred securities, these securities will likely have rights senior to the rights of a common stockholder, which could impair the value of the common stock.

We also have stock options and warrants outstanding to purchase shares of our capital stock. Our stockholders may incur dilution upon exercise of any outstanding stock options and warrants.

The price per share of our common stock being offered may be higher than the net tangible book value per share of our outstanding common stock prior to this offering. Assuming that an aggregate of 6,176,470 shares of our common stock are sold at a price of $1.19 per share, the last reported sale price of our common stock on Nasdaq on September 18, 2025, new investors in this offering will incur immediate dilution of $0.64 per share, representing the difference between our as adjusted net tangible book value per share as of June 30, 2025 after giving effect to this offering and the assumed price. For a more detailed discussion of the foregoing, see the section entitled “Dilution” elsewhere in this prospectus. To the extent that our outstanding stock options or warrants are exercised, there will be further dilution to new investors.

Our cash requirements may vary from those now planned depending upon numerous factors. We expect to require additional capital until our operations generate sufficient revenue to cover our expenses. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. There are no other commitments by any person for future financing. Our securities may be offered to other investors at a price lower than the price per share offered to current stockholders, or upon terms which may be deemed more favorable than those offered to current stockholders. In addition, the issuance of securities in any future financing may dilute an investor’s equity ownership and have the effect of depressing the market price for our securities. Moreover, we may issue derivative securities, including options and/or warrants, from time to time, to procure qualified personnel or for other business reasons. The issuance of any such derivative securities, which is at the discretion of our Board of Directors, may further dilute the equity ownership of our stockholders.

We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by investors in this offering, and investors purchasing shares or other securities in the future could have rights

superior to existing stockholders. The price per share at which we sell additional shares of our common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by investors in this offering. No assurance can be given as to our ability to procure additional financing, if required, and on terms deemed favorable to us. To the extent additional capital is required and cannot be raised successfully, we may then have to limit our then current operations and/or may have to curtail certain, if not all, of our business objectives and plans.

We have a substantial number of convertible securities outstanding. The exercise of our outstanding warrants, conversion of our convertible notes, and exercise of our convertible preferred stock will likely have a dilutive effect on our common stock. The issuance of shares of common stock upon exercise of outstanding options or warrants or conversion of preferred stock could result in substantial dilution to our stockholders, which may have a negative effect on the price of our common stock.

We need to raise funds in the future to execute our business plan. We may seek to raise additional capital to expand our business, pursue strategic investments, and take advantage of financing or other opportunities that we believe to be in our best interests and the interests of our stockholders. Additional capital may be raised through the sale of common or preferred equity or convertible debt securities, entry into debt facilities or other third-party funding arrangements. The sale of equity and convertible debt securities may result in dilution to our stockholders and those securities may have rights senior to those of the Common Stock. Agreements entered into in connection with such capital raising activities could contain covenants that would restrict our operations or require us to relinquish certain rights. Additional capital may not be available on reasonable terms, or at all. If we cannot timely raise any needed funds, we may be forced to reduce our operating expenses, which could adversely affect our ability to implement our long-term strategic roadmap and grow our business.

The publicly traded shares of the Common Stock have experienced, and may experience in the future significant price and volume fluctuations. During the 12 months ended September 12, 2025, the market price of the common stock as reported by Nasdaq has ranged from a high of $14.8399 per share to a low of $1.03 per share. This market volatility could reduce the market price of the common stock without regard to our operating performance. In addition, the trading price of the common stock could change significantly in response to actual or anticipated variations in our quarterly operating results, announcements by us or our competitors, factors affecting the space transportation industry generally, changes in national or regional economic conditions, changes in securities analysts’ estimates for us or our competitors’ or industry’s future performance or general market conditions, making it more difficult for shares of the common stock to be sold at a favorable price or at all. The market price of the common stock could also be reduced by general market price declines or market volatility in the future or future declines or volatility in the prices of stocks for companies in our industry.

We have never declared or paid cash dividends on our common stock. We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends in the foreseeable future. As a result, we expect that only appreciation of the price of our common stock, if any, will provide a return to investors in this offering for the foreseeable future.

We may issue shares of our common stock from time to time in connection with this offering. This issuance from time to time of these new shares of our common stock, or our ability to issue these shares of our common stock in this offering, could result in resales of our common stock by our current stockholders concerned about the potential dilution of their holdings. In turn, these resales could have the effect of depressing the market price for our common stock.

Subject to certain limitations in the sales agreement with the sales agent and compliance with applicable law, we have the discretion to deliver placement notices to the sales agent at any time throughout the term of the sales agreement. The number of shares that are sold by the sales agent after delivering a placement notice will fluctuate based on the market price of the common stock during the sales period and limits we set with the sales agent.

Investors who purchase shares under this prospectus supplement and documents incorporated by reference into this prospectus supplement at different times will likely pay different prices, and so may experience different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices, and numbers of shares sold, and there is no minimum or maximum sales price. Investors may experience declines in the value of their shares as a result of share sales made at prices lower than the prices they paid.

As of the date of this prospectus supplement, we had 673,408 outstanding shares of non-voting Series A Convertible Preferred Stock. The holder of the Series A Convertible Preferred Stock may, at its option, convert each of its shares of Series A Convertible Preferred Stock into ten shares of common stock, subject to the limitations in the Certificate of Designations, provided that such holder hold no more than 9.99% of the outstanding shares of our common stock at any time. The conversion of the non-voting Series A Convertible Preferred Stock of the Company will cause significant dilution to the then holders of our common stock. In addition, the common stock issuable upon conversion of our outstanding non-voting Series A Convertible Preferred Stock may represent overhang that may also adversely affect the market price of our common stock. Overhang occurs when there is a greater supply of a company’s stock in the market than there is demand for that stock, which typically depresses a company’s stock price. If we experience overhang, any additional shares which the then holders of our common stock attempt to sell in the market will only further decrease the market price of our common stock.

We may issue and sell shares of our common stock having aggregate gross proceeds of up to $7,350,000 from time to time under this prospectus and the documents incorporated by reference herein and therein. Because there is no minimum offering amount required as a condition to close this offering, the actual total offering amount, commissions and proceeds to us, if any, are not determinable at this time. The amount of proceeds from this offering will depend upon the number of shares of our common stock sold and the market price at which they are sold. There can be no assurance that we will be able to sell any shares of our common stock under or fully utilize the Sales Agreement with A.G.P. as a source of financing.

We intend to use the net proceeds, if any, from the sales of shares of our common stock offered by this prospectus for working capital and general corporate purposes, including, to acquire, license or invest in assets, businesses, technologies, product candidates or other intellectual property, to make milestone payments and to repurchase securities. We have broad discretion in determining how the proceeds of this offering will be used, and our discretion is not limited by the aforementioned possible uses. Our Board of Directors believes the flexibility in application of the net proceeds is prudent.

As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to be received from this offering. The amounts and timing of our actual expenditures will depend on numerous factors including our operating costs and the amount of funding, if any, received from grants. Accordingly, our management will have broad discretion in the application of the net proceeds, and investors will be relying on the judgment of management regarding the application of the net proceeds from the offering. We may find it necessary or advisable to reallocate the net proceeds of this offering; however, any such reallocation would be substantially limited to the categories set forth above as we do not intend to use the net proceeds for other purposes. Pending such uses set forth above, we plan to invest the net proceeds in government securities and other short-term investment grade, marketable securities.

We have never declared or paid any cash dividends on our capital stock and we do not currently intend to pay any cash dividends on our common stock in the foreseeable future. We expect to retain all available funds and future earnings, if any, to fund the development and growth of our business. Any future determination to pay dividends, if any, on our common stock will be at the discretion of our Board of Directors and will depend on, among other factors, our results of operations, financial condition, capital requirements and contractual restrictions.

Our net tangible book value as of June 30, 2025 was approximately $(10.2) million, or $(1.75) per share. Net tangible book value per share is determined by dividing our total tangible assets, less total liabilities, by the number of shares of our common stock outstanding as of June 30, 2025. Dilution with respect to net tangible book value per share represents the difference between the amount per share paid by purchasers of shares of common stock in this offering and the net tangible book value per share of our common stock immediately after this offering.

Subsequent to June 30, 2025, among other things, (i) we issued 2,836,880 shares of common stock and received aggregate net proceeds of approximately $3.6 million on July 1, 2025 in connection with a registered offering, (ii) we issued 2,431,029 shares of common stock and received net proceeds of approximately $2.5 million in connection with the exercise of certain warrants (iii) we issued 8,696 shares of common stock to a vendor to settle debt of $10,000 and (iv) waived a provision under the Master Services Agreement with VLD, resulting in 477,455 shares of common stock and 673,408 shares of Series A Convertible Preferred Stock (convertible into 6,734,080 shares of common stock) becoming fully vested and the recognition of an asset of approximately $10.7 million. On a pro forma basis after giving effect to these transactions, as of June 30, 2025, our pro forma net tangible book value per share would have been $0.361 per share.

After giving effect to the pro forma adjustments set forth above and to the sale of 6,176,470 shares of our common stock in this offering at an assumed offering price of $1.19 per share, which is the closing price of our common stock on Nasdaq on September 18, 2025, and after deducting the sales agent fees and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value as of June 30, 2025 would have been approximately $13.5 million, or $0.55 per share. This represents an immediate increase in as adjusted net tangible book value of $0.19 per share to existing stockholders and an immediate dilution of $0.64 per share to new investors purchasing securities in this offering. The following table illustrates this per share dilution:

The table and discussion above excludes, as of June 30, 2025:

The above illustration of dilution per share to investors participating in this offering assumes no exercise of outstanding options to purchase our common stock or outstanding warrants to purchase shares of our common stock. To the extent that any of these outstanding options or warrants are exercised or we issue additional shares under our equity incentive plans, there will be further dilution to new investors. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

We entered into the Sales Agreement with A.G.P. under which we may issue and sell from time-to-time shares of our common stock having an aggregate offering price of up to $7,350,000 to or through A.G.P., acting as our sales agent or principal. The sales of shares of our common stock, if any, under this prospectus supplement will be made at market prices by any method deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act, including sales made directly on Nasdaq, on any other existing trading market for our common stock or to or through a market maker. If we and A.G.P. agree on any method of distribution other than sales of our common stock on or through Nasdaq or another existing trading market in the United States at market prices, we will file an additional prospectus supplement to provide information about any such methods of distribution as required by Rule 424(b) under the Securities Act.

Each time that we wish to issue and sell shares of our common stock under the Sales Agreement, we will provide the Sales Agent with a placement notice describing the amount of shares to be sold, the time period during which sales are requested to be made, any limitation on the amount of shares of our common stock that may be sold in any single day, any minimum price below which sales may not be made or any minimum price requested for sales in a given time period and any other instructions relevant to such requested sales. Upon receipt of a placement notice, the Sales Agent, acting as our sales agent, will use commercially reasonable efforts, consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of Nasdaq, to sell shares of our common stock under the terms and subject to the conditions of the placement notice and the sales agreement. We or the Sales Agent may suspend the offering of shares of our common stock pursuant to a placement notice upon notice.

Settlement for sales of shares of common stock, unless the parties agree otherwise, will occur on the first trading day following the date on which any sales are made in return for payment of the net proceeds to us. There are no arrangements to place any of the proceeds of this offering in an escrow, trust or similar account. Sales of shares of our common stock as contemplated in this prospectus will be settled through the facilities of The Depository Trust Company or by such other means as we and the Sales Agent may agree upon.

The Sales Agent will be entitled to compensation at a fixed commission rate of 3.0% of the gross proceeds from the sale of shares of our common stock on our behalf pursuant to the sales agreement. Pursuant to the terms of the sales agreement, we agreed to reimburse the Sales Agent for the documented fees and costs of its legal counsel reasonably incurred in connection with entering into the transactions contemplated by the Sales Agreement in an amount not to exceed $50,000 in the aggregate, in addition to up to $10,000 annually for the Sales Agent’s counsel’s fees and any incidental expenses to be reimbursed by us. We will report at least quarterly the number of shares of common stock sold through the Sales Agent under the Sales Agreement, the net proceeds to us and the compensation paid by us to the Sales Agent in connection with the sales of common stock.

We estimate that the total expenses for this offering, excluding compensation payable to the Sales Agent and certain expenses reimbursable to the Sales Agent under the terms of the Sales Agreement, will be approximately $200,000. The remaining sales proceeds, after deducting any expenses payable by us and any transaction fees imposed by any governmental, regulatory, or self-regulatory organization in connection with the sales, will equal our net proceeds for the sale of such shares of common stock.

Because there are no minimum sale requirements as a condition to this offering, the actual total public offering price, commissions and net proceeds to us, if any, are not determinable at this time. The actual dollar amount and number of shares of common stock we sell through this prospectus will be dependent, among other things, on market conditions and our capital raising requirements.

In connection with the sale of shares of common stock on our behalf, the Sales Agent will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of the Sales Agent will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to the Sales Agent against certain civil liabilities, including liabilities under the Securities Act.

The Sales Agent will not engage in any market making activities involving shares of our common stock while the offering is ongoing under this prospectus if such activity would be prohibited under Regulation M or other anti-manipulation rules under the Securities Act. As our sales agent, the Sales Agent will not engage in any transactions that stabilizes shares of our common stock.

The offering pursuant to the Sales Agreement will terminate upon the earlier of (i) the sale of all shares of common stock subject to the sales agreement and (ii) termination of the sales agreement as permitted therein. We may terminate the sales agreement in our sole discretion at any time by giving one (1) day’s prior notice to the Sales Agent. The Sales Agent may terminate the Sales Agreement under the circumstances specified in the sales agreement and in its sole discretion at any time by giving five (5) days’ prior notice to us.

This prospectus may be made available in electronic format on a website maintained by the Sales Agent, and the Sales Agent may distribute this prospectus electronically.

In connection with the sale of our common stock on our behalf, A.G.P. will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of A.G.P. will be deemed to be underwriting commissions or discounts.

A.G.P. will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus supplement if such activity would be prohibited under Regulation M or other anti-manipulation rules under the Exchange Act or the Securities Act. As our sales agent, A.G.P. will not engage in any transactions that stabilizes our common stock.

We have agreed to indemnify A.G.P. against certain civil liabilities, including liabilities under the Securities Act and the Exchange Act, and to contribute to payments that the A.G.P. may be required to make in respect of such liabilities.

Our common stock is listed on the Nasdaq Capital Market under the symbol “MNTS.”

In the ordinary course of its business activities, A.G.P. and its affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for its own account and for the accounts of its customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates.

The Agent and its affiliates may in the future provide various investment banking, commercial banking, financial advisory, and other financial services for us and our affiliates, for which services they may in the future receive customary fees.

On September 11, 2023, we closed an offering of Common Stock and warrants in which we raised approximately $5,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive Placement Agent in connection with the offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $75,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On October 4, 2023, we closed an offering of Common Stock and warrants in which we raised approximately $4,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $75,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On November 9, 2023, we closed a warrant inducement offering in which we raised approximately $6,500,000 of gross proceeds. A.G.P./Alliance Global Partners served as the exclusive financial advisor in connection with the warrant inducement offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the warrant inducement offering $60,000 for legal expenses incurred by them in connection with the warrant inducement offering.

On January 17, 2024, we closed an offering of Common Stock and warrants in which we raised approximately $4,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $75,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On March 7, 2024, we closed an offering of Common Stock and warrants in which we raised approximately $4,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $75,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On September 17, 2024, we closed an offering of Common Stock and warrants in which we raised approximately $2,750,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0% and warrants to purchase 500,000 shares of Common Stock at an exercise price of $0.6325. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $125,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On December 13, 2024, we entered into a Loan Agreement (the “December 2024 Loan Agreement”) with J.J. Astor & Co. (the “Lender”) pursuant to which we borrowed $2.0 million. A.G.P./Alliance Global Partners served as our financial advisor in connection with the Loan Agreement and received a cash fee equal to 7.5% of the loan amount.

On December 18, 2024, we closed an offering of Common Stock and warrants in which we raised approximately $5,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0% and warrants to purchase 40,000 shares of Common Stock at an exercise price of $6.82. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $95,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On February 11, 2025, we closed an offering of Common Stock and warrants in which we raised approximately $5,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0% and warrants to purchase 63,694 shares of Common Stock at an exercise price of $4.3175. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $95,000 for legal expenses incurred by them in connection with the offering and $10,000 for non-accountable expense reimbursement.

On March 20, 2025, we closed a warrant inducement offering (the “Inducement Warrants”) in which we raised approximately $2.07 million of gross proceeds. A.G.P./Alliance Global Partners served as the exclusive financial advisor in connection with the warrant inducement offering and received a cash fee equal to approximately $145,000. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the warrant inducement offering $35,000 for legal expenses incurred by them in connection with the warrant inducement offering.

On April 12, 2025, we entered into the Master Services Agreement with Velo3D, Inc. A.G.P./Alliance Global Partners served as the exclusive financial advisor in connection with the Master Services Agreement, and agreed to receive a fee equal to 8.0% of the transaction price in the form of a convertible note in the principal amount of $1,200,000 (the “Original Convertible Promissory Note”). On June 17, 2025, we executed an agreement with A.G.P./Alliance Global Partners that amended the Original Convertible Promissory Note that provides that upon the commencement of sales in this offering, the Original Convertible Promissory Note will be null and void and a new convertible note in the principal amount of $500,000 (the “New Convertible Note”) shall be issued by us to A.G.P./Alliance Global Partners and A.G.P./Alliance Global Partners shall have no recourse against us for the $700,000 of principal that it will no longer receive pursuant to the terms of the Original Convertible Promissory Note. The New Convertible Note shall mature 18 months after issuance and be convertible into shares of our common stock at a conversion price of $1.67 per share. Pursuant to FINRA Rule 5110(g)(1), neither the New Convertible Note nor any shares issued upon conversion of the New Convertible Note shall be sold, transferred, assigned, pledged, or hypothecated, or be the subject of any hedging, short sale, derivative, put, or call transaction that would result in the effective economic disposition of the securities by any person for a period of 180 days immediately following the issuance date of the New Convertible Note. We have agreed to file one or more registration statements to register the resale of all securities issuable upon conversion of the New Convertible Note, only one of which shall be at our expense and demand may be made after issuance until the maturity date.

On May 30, 2025, we entered into a private placement for a loan in the principal amount of $1,500,000, as amended on June 17, 2025. A.G.P./Alliance Global Partners served as the exclusive financial advisor in connection with the private placement pursuant to which we issued to the lender a note in the principal amount of $1,012,500 and A.G.P./Alliance Global Partners will receive a $75,000 cash fee. In addition, when the second tranche of notes is issued to the lender A.G.P./Alliance Global Partners will receive an additional cash fee of $75,000.

On July 1, 2025, we closed an offering of Common Stock and warrants in which we raised approximately $4,000,000 of gross proceeds. A.G.P./Alliance Global Partners served as our exclusive placement agent in connection with the offering and received a cash fee equal to 7.0%. In addition, we reimbursed A.G.P./Alliance Global Partners at the closing of the offering $105,000 for legal expenses incurred by them in connection with the offering reimbursement.

The validity of the securities offered hereby will be passed upon for us by Bradley Arant Boult Cummings LLP. A.G.P./Alliance Global Partners is being represented in connection with this offering by Thompson Hine LLP.

The consolidated financial statements of the Company and subsidiaries as of and for the year ended December 31, 2023 and 2024, incorporated by reference in this prospectus, have been audited by Frank, Rimerman + Co. LLP, an independent registered public accounting firm, as stated in their report. Such consolidated financial statements are incorporated by reference in reliance upon the report of such firm given their authority as experts in accounting and auditing.

We are subject to the periodic reporting requirements of the Exchange Act, and we will file periodic reports, proxy statements and other information with the SEC. These periodic reports, proxy statements and other information are available at www.sec.gov. We also maintain a website at www.momentus.space, at which you may access these materials free of charge as soon as reasonably practicable after they are electronically filed with, or furnished to, the SEC. Information contained on or accessible through our website is not a part of this prospectus, and the inclusion of our website address in this prospectus is an inactive textual reference only. We will provide you without charge, upon your oral or written request, with a copy of any or all reports, proxy statements and other documents we file with the SEC, as well as any or all of the documents incorporated by reference in this prospectus or the registration statement (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into such documents). Requests for such copies should be directed to:

Momentus Inc.

Attn: John C. Rood

Chief Executive Officer

3901 N. First Street

San Jose, CA 95134

Telephone: (650) 564-7820

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus.

We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-12584):

All reports and other documents that we file with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act on or after the date of the filing of the registration statement of which this prospectus supplement forms a part and prior to effectiveness of the registration statement, and on or after the date of this prospectus supplement but before the termination of the offering of the securities hereunder will also be considered to be incorporated by reference into this prospectus supplement from the date of the filing of these reports and documents, and will supersede the information herein; provided, however, that all reports, exhibits and other information that we “furnish” to the SEC will not be considered incorporated by reference into this prospectus. We undertake to provide without charge to each person (including any beneficial owner) who receives a copy of this prospectus supplement, upon written or oral request, a copy of all of the preceding documents that are incorporated by reference (other than exhibits, unless the exhibits are specifically incorporated by reference into these documents). You may request a copy of these materials in the manner set forth under the heading “Where You Can Find More Information,” above.

 

   , 2025

The following sets forth the estimated costs and expenses, all of which shall be borne by Momentus Inc. (the “Registrant”), in connection with the offering of the securities pursuant to this registration statement.

Section 145 of the Delaware General Corporation Law (the “DGCL”) provides that a corporation may indemnify directors and officers as well as other employees and individuals against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by such person in connection with any threatened, pending or completed actions, suits or proceedings in which such person is made a party by reason of such person being or having been a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise. The DGCL provides that Section 145 is not exclusive of other rights to which those seeking indemnification may be entitled under any bylaws, agreement, vote of stockholders or disinterested directors or otherwise. The registrant’s Second Amended and Restated Certificate of Incorporation, as amended, and Amended and Restated Bylaws, as amended, provide for indemnification by the registrant of its directors and officers to the fullest extent permitted by the DGCL.

Section 102(b)(7) of the DGCL permits a corporation to provide in its certificate of incorporation that a director of the corporation shall not be personally liable to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except for liability (1) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (2) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (3) for unlawful payments of dividends or unlawful stock repurchases, redemptions or other distributions, or (4) for any transaction from which the director derived an improper personal benefit. The registrant’s Second Amended and Restated Certificate of Incorporation, as amended, provides for such limitation of liability to the fullest extent permitted by the DGCL.

The registrant has entered into, and expects to continue to enter into, indemnification agreements with each of its directors and executive officers. These agreements provide that the registrant will indemnify each of its directors and such officers to the fullest extent permitted by law.

Any underwriting agreement or distribution agreement that the registrant enters into with any underwriters or agents involved in the offering or sale of any securities registered hereby may require such underwriters or dealers to indemnify the registrant, some or all of its directors and officers and its controlling persons, if any, for specified liabilities, which may include liabilities under the Securities Act.

The registrant also maintains standard policies of insurance under which coverage is provided to its directors and officers against loss arising from claims made by reason of breach of duty or other wrongful act, while acting in their capacity as directors and officers of the registrant.

The exhibits to this registration statement are listed in the Exhibit Index to this registration statement, which immediately precedes the Signature Page and which Exhibit Index is hereby incorporated by reference.

The undersigned registrant hereby undertakes:

provided, however, that the undertakings set forth in paragraphs (1)(i), (1)(ii) and (1)(iii) above do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, that are incorporated by reference in this registration statement or are contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

Pursuant to the requirements of the Securities Act of 1933, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized on September 19, 2025.

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints John C. Rood and Lon Ensler, and each and either of them, his true and lawful agent, proxy and attorney-in-fact, with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to (i) act on, sign and file with the Securities and Exchange Commission any and all amendments (including post-effective amendments) to this registration statement together with all schedules and exhibits thereto and any subsequent registration statement filed pursuant to Rule 462(b) under the Securities Act, together with all schedules and exhibits thereto, (ii) act on, sign and file such certificates, instruments, agreements and other documents as may be necessary or appropriate in connection therewith, (iii) act on and file any supplement to any prospectus included in this registration statement or any such amendment or any subsequent registration statement filed pursuant to Rule 462(b) under the Securities Act and (iv) take any and all actions which may be necessary or appropriate to be done, as fully for all intents and purposes as he might or could do in person, hereby approving, ratifying and confirming all that such agent, proxy and attorney-in-fact or any of his substitutes may lawfully do or cause to be done by virtue thereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.