Sec Form 4 Filing - CRANDELL KEITH @ 908 Devices Inc. - 2020-12-22

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person CRANDELL KEITH 2. Issuer Name and Ticker or Trading Symbol 908 Devices Inc. [ MASS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 8755 WEST HIGGINS ROAD, SUITE 1025 3. Date of Earliest Transaction (MM/DD/YY) 12/22/2020 (Street) CHICAGO, IL60631 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 5,425,045 I See Footnote ( 2 ) Common Stock, par value $0.001 12/22/2020 P 300,000 A $ 20 5,725,045 I See Footnote ( 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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 0 I See Footnote ( 2 ) Series B Preferred Stock ( 1 ) 12/22/2020 C 981,443 ( 1 ) ( 1 ) Common Stock, par value $0.001 981,443 $ 0 0 I See Footnote ( 2 ) Series C Preferred Stock ( 1 ) 12/22/2020 C 669,977 ( 1 ) ( 1 ) Common Stock, par value $0.001 669,977 $ 0 0 I See Footnote ( 2 ) Series D Preferred Stock ( 1 ) 12/22/2020 C 665,661 ( 1 ) ( 1 ) Common Stock, par value $0.001 665,661 $ 0 0 I See Footnote ( 2 ) Series E Preferred Stock ( 1 ) 12/22/2020 C 180,578 ( 1 ) ( 1 ) Common Stock, par value $0.001 180,578 $ 0 0 I See Footnote ( 2 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other CRANDELL KEITH 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X X Signatures /s/ Michael S. Turner, as Attorney-in-Fact 12/22/2020 Signature of Reporting Person Date

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. The reporting person is a managing director of ARCH VII LLC, and may be deemed to beneficially own the securities held by ARCH Fund VII. The reporting person disclaims beneficial ownership of such securities, except to the extent of his 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 ARCH Venture Fund VII, L.P.

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).

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