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* ARCH Venture Fund VII, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol 908 Devices Inc. [ MASS ]	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) 12/22/2020
	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

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
Common Stock, par value $0.001	12/22/2020		C		5,425,045	A	(1)	5,425,045	D(2)
Common Stock, par value $0.001	12/22/2020		P		300,000	A	$20	5,725,045	D(2)

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
Series A Preferred Stock	(1)	12/22/2020		C			2,927,386	(1)	(1)	Common Stock, par value $0.001	2,927,386	$0.00	0	D(2)
Series B Preferred Stock	(1)	12/22/2020		C			981,443	(1)	(1)	Common Stock, par value $0.001	981,443	$0.00	0	D(2)
Series C Preferred Stock	(1)	12/22/2020		C			669,977	(1)	(1)	Common Stock, par value $0.001	669,977	$0.00	0	D(2)
Series D Preferred Stock	(1)	12/22/2020		C			665,661	(1)	(1)	Common Stock, par value $0.001	665,661	$0.00	0	D(2)
Series E Preferred Stock	(1)	12/22/2020		C			180,578	(1)	(1)	Common Stock, par value $0.001	180,578	$0.00	0	D(2)

1. Name and Address of Reporting Person* ARCH Venture Fund VII, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Partners VII, L.P. (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* ARCH Venture Partners VII, LLC (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* BYBEE CLINTON (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

1. Name and Address of Reporting Person* NELSEN ROBERT (Last) (First) (Middle) 8755 WEST HIGGINS ROAD SUITE 1025 (Street) CHICAGO IL 60631 (City) (State) (Zip)

Explanation of Responses:

1. Each share of Series A Preferred Stock, Series B Preferred Stock, Series C Preferred Stock, Series D Preferred Stock and Series E Preferred Stock (collectively, the "Preferred Shares") converted into 0.61459 shares of the Issuer's Common Stock automatically upon the closing of the Issuer's initial public offering without payment of additional consideration. The Preferred Shares were convertible at any time at the holder's election and automatically upon the closing of the Issuer's initial public offering, and had no expiration date.

2. The securities are owned directly by ARCH Venture Fund VII, L.P. ("ARCH Fund VII"). The sole general partner of ARCH Fund VII is ARCH Venture Partners VII, L.P. ("ARCH Partners VII"), which may be deemed to be the beneficial owner of the securities held by ARCH Fund VII. The sole general partner of ARCH Partners VII is ARCH Venture Partners VII, LLC ("ARCH VII LLC"), which may be deemed to be the beneficial owner of the securities held by ARCH Fund VII. ARCH Partners VII and ARCH VII LLC disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein. The managing directors of ARCH VII LLC are Keith Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the securities held by ARCH Fund VII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein.

Remarks:

This is one of two Forms 4 filed on the date hereof in respect of these securities. The Reporting Person for the other Form 4 is Keith Crandell.

	/s/ Mark McDonnell, as attorney-in-fact for Keith Crandell, Managing Director of the general partner of the general partner of ARCH Fund VII	12/22/2020
	/s/ Mark McDonnell, as attorney-in-fact for Keith Crandell, Managing Director of the general partner of ARCH Partners VII	12/22/2020
	/s/ Mark McDonnell, as attorney-in-fact for Keith Crandell, Managing Director of ARCH VII LLC	12/22/2020
	/s/ Mark McDonnell, as attorney-in-fact for Clinton Bybee	12/22/2020
	/s/ Mark McDonnell, as attorney-in-fact for Robert Nelsen	12/22/2020
	** Signature of Reporting Person	Date
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* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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