[SCHEDULE 13G/A] 908 Devices Inc. Amended Passive Investment Disclosure
ARCH Venture Fund VII reports 5.73M shares in 908 Devices
ARCH Venture Fund VII and affiliated reporting persons amend a Schedule 13G/A to report beneficial ownership of 5,725,045 shares of Common Stock of 908 Devices Inc. The filing states the Record Shares are held by ARCH Venture Fund VII as of March 31, 2026.
ARCH Venture Fund VII and affiliated reporting persons amend a Schedule 13G/A to report beneficial ownership of 5,725,045 shares of Common Stock of 908 Devices Inc. The filing states the Record Shares are held by ARCH Venture Fund VII as of March 31, 2026. The percentage on the cover pages is 15.1% for the reporting entities and 15.3% for Keith Crandell, with the latter reflecting vested options, 57,794 vested option shares, 25,291 RSUs and 1,086 options vesting within sixty days. The percentage figures are calculated using 37,813,621 shares outstanding as of May 4, 2026, per the issuer’s Form 10-Q.
Positive
None.
Negative
None.
Insights
Registering institutional holdings and manager-level shared voting/ecision power.
The amendment lists 5,725,045 shares held of record by ARCH Venture Fund VII and attributes shared voting and dispositive power across related partnership and managing director entities. The filing clarifies control chains: AVP VII LP and AVP VII LLC are reported as the general partner entities.
The reported percentages (15.1% and 15.3%) use the issuer’s outstanding share count of 37,813,621 as of May 4, 2026. Subsequent disclosures in regulatory filings would show any changes in ownership or voting power.
Holds and option/RSU detail show managerial economic exposure.
The filing notes that Keith Crandell’s reported 5,809,216 shares count assumes conversion/issuance of 57,794 vested options, 25,291 RSUs and 1,086 options vesting within sixty days. These figures are used to compute the 15.3% percentage on the cover sheet.
Cash‑flow treatment or intent to trade is not stated in the excerpt; changes to the public position would appear in future amendments or Forms 4 if open‑market transactions occur.
Key Figures
Record Shares:5,725,045 sharesOutstanding Shares Used for Percentage:37,813,621 sharesReported Percentage (entities):15.1%+4 more
7 metrics
Record Shares5,725,045 sharesRecord owner as of March 31, 2026
Outstanding Shares Used for Percentage37,813,621 sharesShares outstanding as of May 4, 2026 per Form 10-Q
Reported Percentage (entities)15.1%Cover page percentage for reporting entities
Crandell total (assumed)5,809,216 sharesIncludes vested options, RSUs, and near‑term vesting options
Vested option shares57,794 sharesVested options held by Keith Crandell
RSUs25,291 unitsFully vested restricted stock units held by Keith Crandell
Options vesting within 60 days1,086 sharesOptions to vest within sixty days for Keith Crandell
Key Terms
beneficially owned, RSUs, shared dispositive power
3 terms
beneficially ownedregulatory
"ARCH Venture Fund VII is the record owner of 5,725,045 shares of Common Stock (the "Record Shares")"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
RSUsfinancial
"25,291 fully vested restricted stock units ("RSUs")"
RSUs, or restricted stock units, are a form of company shares given to employees as part of their compensation. They are typically awarded with certain restrictions, such as a waiting period before they can be fully owned or sold, similar to earning a gift that becomes fully yours over time. For investors, RSUs can impact a company's stock offerings and reflect how much the company relies on stock-based incentives to attract and retain talent.
shared dispositive powerregulatory
"Shared Dispositive Power 5,725,045.00"
FAQ
What stake does ARCH Venture Fund VII report in 908 Devices (MASS)?
ARCH Venture Fund VII reports beneficial ownership of 5,725,045 shares of Common Stock as of March 31, 2026. The cover percentage for the reporting entities is listed as 15.1%, using the issuer’s outstanding share count.
How is Keith Crandell’s 15.3% ownership calculated?
Crandell’s 15.3% figure assumes issuance of 57,794 vested option shares, 25,291 RSUs, and 1,086 options vesting within sixty days. The percentage uses 37,813,621 shares outstanding as of May 4, 2026.
Which entities share voting and dispositive power over the reported shares?
The filing states shared voting and dispositive power across ARCH Venture Fund VII, ARCH Venture Partners VII, L.P. and ARCH Venture Partners VII, LLC, with Managing Directors named as sharing direction of vote and disposition.
Does the filing show any recent sales or purchases of the shares?
No transaction intent or open‑market activity is disclosed in this amendment. The report lists beneficial ownership and option/RSU holdings; any purchases or sales would appear in separate Forms 4 or later amendments.
What outstanding share count does the filing use to compute percentages?
Percentages on the cover pages are based on 37,813,621 shares of Common Stock outstanding as of May 4, 2026, per the issuer’s Form 10-Q referenced in the amendment.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 5)
908 Devices Inc.
(Name of Issuer)
Common Stock par value $0.001 per share
(Title of Class of Securities)
65443P102
(CUSIP Number)
03/31/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
ARCH Venture Fund VII, L.P.
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,725,045.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.1 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
ARCH Venture Partners VII, L.P.
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,725,045.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.1 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
ARCH Venture Partners VII, LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,725,045.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.1 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
Keith Crandell
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
84,171.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
84,171.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,809,216.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.3 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
Clinton Bybee
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,725,045.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.1 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
CUSIP Number(s):
65443P102
1
Names of Reporting Persons
Robert Nelsen
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,725,045.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,725,045.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,725,045.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
15.1 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
908 Devices Inc.
(b)
Address of issuer's principal executive offices:
44 Third Avenue, Burlington, MA 01803
Item 2.
(a)
Name of person filing:
ARCH Venture Fund VII, L.P. ("ARCH Venture Fund VII"); ARCH Venture Partners VII, L.P. ("AVP VII LP"); ARCH Venture Partners VII, LLC ("AVP VII LLC") (collectively, the "Reporting Entities" and individually, each a "Reporting Entity"); and Keith Crandell ("Crandell"), Robert Nelsen ("Nelsen") and Clinton Bybee ("Bybee") (collectively, the "Managing Directors" and individually, each a "Managing Director"). The Reporting Entities and the Managing Directors collectively are referred to as the "Reporting Persons". The Reporting Persons are filing this report with respect to shares of Common Stock, par value $0.001 per share (the "Common Stock") of 908 Devices Inc. (the "Issuer").
(b)
Address or principal business office or, if none, residence:
8755 W. Higgins Avenue, Suite 1025, Chicago, IL 60631
(c)
Citizenship:
ARCH Venture Fund VII and AVP VII LP are limited partnerships organized under the laws of the State of Delaware. AVP VII LLC is a limited liability company organized under the laws of the State of Delaware. Each Managing Director is a US citizen.
(d)
Title of class of securities:
Common Stock par value $0.001 per share
(e)
CUSIP No.:
65443P102
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
ARCH Venture Fund VII is the record owner of 5,725,045 shares of Common Stock (the "Record Shares") as of March 31, 2026. AVP VII LP, as the sole general partner of ARCH Venture Fund VII, may be deemed to beneficially own the Record Shares. AVP VII LLC, as the sole general partner of AVP VII, may be deemed to beneficially own the Record Shares. As managing directors of AVP VII LLC, each Managing Director may also be deemed to share the power to direct the disposition and vote of the Record Shares.
In addition, as of March 31, 2026, Crandell is a holder of vested options to purchase 57,794 shares of Common Stock (the "Vested Option Shares"), 25,291 fully vested restricted stock units ("RSUs"), and options to purchase 1,086 shares of Common Stock vesting within sixty days (the "Unvested Option Shares").
The information required by Item 4(b) is incorporated by reference to Row 11 of the cover pages hereto. The percentage set forth on the cover sheet for each Reporting Person is based upon 37,813,621 shares of Common Stock outstanding as of May 4, 2026, as reported on the Issuer's Quarterly Report on Form 10-Q as filed with the Securities and Exchange Commission on May 6, 2026, and in the case of Crandell, assumes the issuance of the Vested Option Shares, shares underlying the RSUs, and the Unvested Option Shares.
Each Reporting Person disclaims beneficial ownership of such shares of Common Stock except for the shares, if any, such Reporting Person holds of record.
(b)
Percent of class:
See row 11 of the cover pages.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See row 5 of the cover pages.
(ii) Shared power to vote or to direct the vote:
See row 6 of the cover pages.
(iii) Sole power to dispose or to direct the disposition of:
See row 7 of the cover pages.
(iv) Shared power to dispose or to direct the disposition of:
See row 8 of the cover pages.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
Not Applicable
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
Not Applicable
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
ARCH Venture Fund VII, L.P.
Signature:
/s/ ARCH Venture Partners VII, L.P.
Name/Title:
its General Partner
Date:
05/15/2026
Signature:
ARCH Venture Partners VII, LLC
Name/Title:
its General Partner
Date:
05/15/2026
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:
05/15/2026
ARCH Venture Partners VII, L.P.
Signature:
/s/ ARCH Venture Parnters VII, LLC
Name/Title:
its General Partner
Date:
05/15/2026
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:
05/15/2026
ARCH Venture Partners VII, LLC
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:
05/15/2026
Keith Crandell
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Keith Crandell
Date:
05/15/2026
Clinton Bybee
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Clinton Bybee
Date:
05/15/2026
Robert Nelsen
Signature:
/s/ Mark McDonnell*
Name/Title:
Mark McDonnell, as Attorney-in-Fact for Robert Nelsen
Date:
05/15/2026
Comments accompanying signature: * This Schedule 13G was executed by Mark McDonnell pursuant to Powers of Attorney dated May 7, 2013 and July 26, 2017, filed as Exhibit 2.0 and Exhibit 2.1 to the Schedule 13G filed with the Securities and Exchange Commission on February 14, 2019 and incorporated herein by reference.
