SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Prime Movers Lab Fund I LP (Last) (First) (Middle) P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Momentus Inc. [ MNTS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 09/07/2023
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person
	Rule 10b5-1(c) Transaction Indication Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A common stock	09/07/2023		S		11,748	D	$6.5075(7)	234,295	D(1)(6)
Class A common stock	09/07/2023		S		4,656	D	$6.5075(7)	92,871	I	Held by Momentus PML SPV 1 LP(2)(6)
Class A common stock	09/07/2023		S		917	D	$6.5075(7)	18,300	I	Held by Momentus PML SPV 2 LP(3)(6)
Class A common stock	09/07/2023		S		2,276	D	$6.5075(7)	45,387	I	Held by Momentus PML SPV 3 LP(4)(6)
Class A common stock	09/07/2023		S		906	D	$6.5075(7)	18,080	I	Held by Prime Movers Growth Fund I LP(5)(6)
Class A common stock	09/08/2023		S		6,269	D	$5.8145(8)	228,026	D(1)(6)
Class A common stock	09/08/2023		S		2,485	D	$5.8145(8)	90,386	I	Held by Momentus PML SPV 1 LP(2)(6)
Class A Common Stock	09/08/2023		S		490	D	$5.8145(8)	17,810	I	Held by Momentus PML SPV 2 LP(3)(6)
Class A Common Stock	09/08/2023		S		1,215	D	$5.8145(8)	44,172	I	Held by Momentus PML SPV 3 LP(4)(6)
Class A Common Stock	09/08/2023		S		484	D	$5.8145(8)	17,596	I	Held by Prime Movers Growth Fund I LP(5)(6)
Class A Common Stock	09/11/2023		S		4,526	D	$5.5697(9)	223,500	D(1)(6)
Class A Common Stock	09/11/2023		S		1,794	D	$5.5697(9)	88,592	I	Held by Momentus PML SPV 1 LP(2)(6)
Class A Common Stock	09/11/2023		S		354	D	$5.5697(9)	17,456	I	Held by Momentus PML SPV 2 LP(3)(6)
Class A Common Stock	09/11/2023		S		877	D	$5.5697(9)	43,295	I	Held by Momentus PML SPV 3 LP(4)(6)
Class A Common Stock	09/11/2023		S		349	D	$5.5697(9)	17,247	I	Held by Prime Movers Growth Fund I LP(5)(6)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* Prime Movers Lab Fund I LP (Last) (First) (Middle) P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

1. Name and Address of Reporting Person* Sloss Dakin (Last) (First) (Middle) C/O PRIME MOVERS LAB, P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

1. Name and Address of Reporting Person* Prime Movers Growth Fund I LP (Last) (First) (Middle) P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

1. Name and Address of Reporting Person* Momentus PML SPV 1 LP (Last) (First) (Middle) C/O PRIME MOVERS LAB, P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

1. Name and Address of Reporting Person* MOMENTUS PML SPV 2 LP (Last) (First) (Middle) C/O PRIME MOVERS LAB, P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

1. Name and Address of Reporting Person* Momentus PML SPV 3 LP (Last) (First) (Middle) C/O PRIME MOVERS LAB, P.O. BOX 12829 (Street) JACKSON WY 83002 (City) (State) (Zip)

Explanation of Responses:

1. Held by Prime Movers Lab Fund I LP ("PML"). Prime Movers Lab GP I LLC ("PML GP") is the general partner of PML.

2. Held by Momentus PML SPV 1 LP ("PML SPV 1"). PML GP is the general partner of PML SPV 1.

3. Held by Momentus PML SPV 2 LP ("PML SPV 2"). Prime Movers Lab GP II LLC ("PML GP II") is the general partner of PML SPV 2.

4. Held by Momentus PML SPV 3 LP ("PML SPV 3"). PML GP II is the general partner of PML SPV 3.

5. Held by Prime Movers Growth Fund I LP ("PM Growth"). Prime Movers Growth GP I LLC ("PM Growth GP") is the general partner of PM Growth.

6. Dakin Sloss is the manager of PML GP, PML GP II and PM Growth GP, and may be deemed to beneficially own the securities held by PML, PML SPV 1, PML SPV 2, PML SPV 3 and PM Growth. Mr. Sloss disclaims any beneficial ownership of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein.

7. The price of $6.5075 per share represents a weighted average of purchase prices ranging from $6.010 to $7.350 per share. The reporting person undertakes to provide upon request by the Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.

8. The price of $5.8145 per share represents a weighted average of purchase prices ranging from $5.445 to $6.558 per share. The reporting person undertakes to provide upon request by the Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.

9. The price of $5.5697 per share represents a weighted average of purchase prices ranging from $5.271 to $5.81 per share. The reporting person undertakes to provide upon request by the Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased or sold at each separate price.

	/s/ Taylor Frankel, Authorized Person on behalf of the General Partner of each Reporting Person	09/11/2023
	Dakin Sloss /s/ Taylor Frankel, Attorney-in-fact	09/11/2023
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.