Momentus Inc.-美国股市招股说明书(2026年2月6日版)

PROSPECTUS SUPPLEMENT (To Prospectus Supplement dated December 12, 2025)(To Prospectus Supplement dated October 20, 2025)((To Prospectus Supplement dated October 10, 2025) Up to $4,177,347of Common Stock This prospectus supplement (the "Prospectus Supplement") amends and supplements the prospectus supplement dated December 12,2025, the prospectus supplement dated October 20, 2025, the prospectus supplement dated October 10, 2025, the prospectussupplement dated September 30, 2025 and the accompanying base prospectus dated September 30, 2025 filed with the Securities andexchange Commission as part of our registration statement on Form S-3 (collectively, the "ATM Prospectus"), relating to the offer andsale of shares of our Class A common stock, par value $0.00001 per share (“common stock” from time to time pursuant to the terms ofthe sales agreement dated September 19, 2025 (the "ATM Agreement") with A.G.P./Alliance Global Partners (the "Sales Agent"), 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, theaggregate market value of our common stock held by non-affiliates pursuant to General Instruction I.B.6 of Form S-3 is $64,868,408,which was calculated based on 3,842,710 shares of our outstanding common stock held by non-affiliates and a price of $16.88 pershare, the closing price of our common stock on December 11, 2025, which is the highest closing sale price of our common stock onthe Nasdaq Capital Market (“Nasdaq”) within the prior 60 days. As of the date of this Prospectus Supplement, we have sold anaggregate of $17,445,455 of shares of our common stock pursuant to General Instruction I.B.6 of Form S-3 during the 12 calendarmonths prior to, and including, the date of this Prospectus Supplement. As such, $4,177,347 is available to be sold pursuant to this We are filing this Prospectus Supplement to amend the ATM Prospectus to update the maximum amount of shares that we are eligibleto sell under General Instruction I.B.6. As a result of these limitations, we may offer and sell shares of our common stock having anaggregate offering price of up to $4,177,347 (which does not include the $17,445,455 of shares previously sold under the ATMAgreement) pursuant to this Prospectus Supplement in accordance with the terms of the ATM Agreement. However, in the event thatour public float increases, we may sell additional securities in public primary offerings on Form S-3 with a value up to one-third of ourpublic 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 common stock is listed on Nasdaq under the symbol “MNTS.” On February 6, 2026, the last reported sale price of our commonstock on Nasdaq was $6.00 per share. Investing in our common stock involves a high degree of risk. Before making an investment decision, please read theinformation under the heading “Risk Factors” beginning on page S-12 of the ATM Prospectus and in the documentsincorporated by reference into this prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is February 6, 2026