MNTS prospectus supplement shows $4.79M ATM offering room

Rhea-AI Filing Summary

Momentus Inc. filed a prospectus supplement to update how much Class A common stock it may sell under an at-the-market (ATM) sales agreement with A.G.P./Alliance Global Partners. The company reports an aggregate market value of common stock held by non-affiliates of $9,229,204.68, based on 14,496,133 non-affiliate shares and a closing price of $1.91 on August 13, 2025. Momentus has sold $4,440,368.79 of stock under the Form S-3 limit in the prior 12 months and therefore has $4,788,835.89 of additional capacity to sell under General Instruction I.B.6 of Form S-3. The company notes the one-third public-float cap applies while public float remains below $75.0M. Its Nasdaq ticker is MNTS and the last reported sale price was $1.37 on October 10, 2025.

Positive

• Clear disclosure of remaining ATM selling capacity: $4,788,835.89
• Compliance with Form S-3 General Instruction I.B.6 and transparent prior sales: $4,440,368.79 sold in last 12 months

Negative

• Limited public float (non-affiliate market value of $9,229,204.68) constrains ATM selling capacity under the one-third rule
• Small remaining capacity relative to potential needs: only $4.79M available unless public float increases

Insights

Capital Markets Analyst

TL;DR: The filing updates available ATM capacity under Form S-3 limits: $4.79M remains.

The company quantifies its public-float-based selling capacity using General Instruction I.B.6: with a non-affiliate market value of $9.23M, the one-third cap constrains primary offerings while public float stays below $75.0M. The supplement records $4.44M sold in the prior 12 months and calculates remaining capacity at $4.79M.

Primary dependencies are the reported non-affiliate market value and future share price movements; if public float rises above $75.0M, the cap would no longer apply and additional capacity could be available. Watch for changes in market price and any subsequent prospectus supplement before new sales.

Filed Pursuant to Rule 424(b)(5)

Registration No. 333-290425

PROSPECTUS SUPPLEMENT

(To Prospectus and Prospectus Supplement dated September 30, 2025)

Up to $4,788,835.89

of Common Stock

This prospectus supplement (the “Prospectus Supplement”) amends and supplements the prospectus supplement dated September 30, 2025 and the accompanying base prospectus dated September 30, 2025 filed with the Securities and exchange Commission as part of our registration statement on Form S-3 (collectively, the “ATM Prospectus”), relating to the offer and sale of shares of our Class A common stock, par value $0.00001 per share (“common stock” from time to time pursuant to the terms of the sales agreement dated September 19, 2025 (the “ATM Agreement”) with A.G.P./Alliance Global Partners (the “Sales Agent”), acting as our sales agent or principal. This Prospectus Supplement should be read in conjunction with the ATM Prospectus, and is qualified by reference thereto, except to the extent that the information herein amends or supersedes the information contained in the ATM Prospectus. This Prospectus Supplement is not complete without and may only be delivered or utilized in connection with the ATM Prospectus, and any future amendments or supplements thereto.

We are subject to the offering limits in General Instruction I.B.6 of Form S-3. As of the date of this Prospectus Supplement, the aggregate market value of our common stock held by non-affiliates pursuant to General Instruction I.B.6 of Form S-3 is $9,229,204.68, which was calculated based on 14,496,133 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 sale price of our common stock on the Nasdaq Capital Market (“Nasdaq”) within the prior 60 days. As of the date of this Prospectus Supplement, we have sold an aggregate of $4,440,368.79 of shares of our common stock pursuant to General Instruction I.B.6 of Form S-3 during the 12 calendar months prior to, and including, the date of this Prospectus Supplement. As such, $4,788,835.89 is available to be sold pursuant to this Prospectus Supplement. Pursuant to General Instruction I.B.6 of Form S-3, in no event will we sell securities in public primary offerings on Form S-3 with a value exceeding one-third of our public float (as defined by General Instruction I.B.6) in any twelve calendar month period so long as our public float remains below $75.0 million.

We are filing this Prospectus Supplement to amend the ATM Prospectus to update the maximum amount of shares that we are eligible to sell under General Instruction I.B.6. As a result of these limitations, we may offer and sell shares of our common stock having an aggregate offering price of up to $4,788,835.89 (which does not include the $4,440,368.79 of shares previously sold under the ATM Agreement) pursuant to this Prospectus Supplement in accordance with the terms of the ATM Agreement. However, in the event that our public float increases, we may sell additional securities in public primary offerings on Form S-3 with a value up to one-third of our public float, in each case calculated pursuant to General Instruction I.B.6 and subject to the terms of the Agreement. In the event that our public float increases above $75.0 million, we will no longer be subject to the limits in General Instruction I.B.6 of Form S-3. If our public float increases such that we may sell additional amounts under the ATM Agreement and the registration statement of which this Prospectus Supplement and the ATM Prospectus are a part, we will file another prospectus supplement prior to making additional sales.

Our common stock is listed on Nasdaq under the symbol “MNTS.” On October 10, 2025, the last reported sale price of our common stock on Nasdaq was $1.37 per share.

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 the ATM Prospectus 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 supplement is October 10, 2025

FAQ

How much common stock can Momentus (MNTS) still sell under this prospectus supplement?

Momentus can sell up to $4,788,835.89 of common stock under the amended prospectus supplement.

How much has Momentus sold under Form S-3 in the past 12 months?

The company has sold an aggregate of $4,440,368.79 of common stock pursuant to General Instruction I.B.6 during the 12 calendar months prior to this supplement.

What public-float figure did Momentus use to calculate ATM capacity?

Momentus reported the aggregate market value of common stock held by non-affiliates as $9,229,204.68, based on 14,496,133 shares and a closing price of $1.91 on August 13, 2025.

Under what condition would Momentus be able to sell more than the stated amount?

If the company’s public float increases, it may sell additional securities up to one-third of its public float or, if public float exceeds $75.0M, the one-third Form S-3 limit would no longer apply.

What is Momentus’s Nasdaq ticker and most recent reported sale price in the filing?

The Nasdaq ticker is MNTS and the last reported sale price cited is $1.37 on October 10, 2025.