ARCH funds disclose 13.9% ownership of 908 Devices Inc. (MASS) in latest 13G/A

Rhea-AI Filing Summary

908 Devices Inc. received an amended Schedule 13G reporting that ARCH Venture Fund VII, L.P. is the record owner of 5,725,045 shares of Common Stock as of June 30, 2026. Through their general-partner structure, ARCH Venture Partners VII, L.P. and ARCH Venture Partners VII, LLC may be deemed to beneficially own the same shares, with shared voting and dispositive power.

Based on 41,333,705 shares of Common Stock outstanding as of August 7, 2026, each of the ARCH entities reports beneficial ownership of 13.9% of the class. Managing director Keith Crandell reports beneficial ownership of 5,824,877 shares, or 14.1%, including options and restricted stock units, and has both sole and shared voting and dispositive power over different portions of these holdings. The filing notes that each reporting person disclaims beneficial ownership except for shares held of record.

Key Figures

Record shares owned by ARCH Venture Fund VII: 5,725,045 shares ARCH entities ownership percentage: 13.9 % Crandell total beneficial ownership: 5,824,877 shares +5 more

8 metrics

Record shares owned by ARCH Venture Fund VII 5,725,045 shares Common Stock record holdings as of June 30, 2026

ARCH entities ownership percentage 13.9 % Percent of Common Stock class based on 41,333,705 shares outstanding

Crandell total beneficial ownership 5,824,877 shares Includes Record Shares, options and RSUs; 14.1% of class

Crandell ownership percentage 14.1 % Percent of Common Stock assuming issuance of vested and near-term options

Shares outstanding 41,333,705 shares Common Stock outstanding as of August 7, 2026

Crandell vested options 59,423 shares Vested options to purchase Common Stock as of June 30, 2026

Crandell vested RSUs 39,374 units Fully vested restricted stock units held by Crandell

Crandell near-term vesting options 1,035 shares Options vesting within sixty days, counted in his ownership

Key Terms

beneficial ownership, shared voting power, shared dispositive power, restricted stock units, +1 more

5 terms

beneficial ownership financial

"The Reporting Persons are filing this report with respect to shares of Common Stock"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

shared voting power financial

"Shared Voting Power 5,725,045.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"Shared Dispositive Power 5,725,045.00"

restricted stock units financial

"Crandell is a holder of vested options to purchase 59,423 shares of Common Stock"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Powers of Attorney regulatory

"pursuant to Powers of Attorney included as Exhibit 2 to the Form 13G"

A power of attorney is a legal document that lets one person give another the authority to act on their behalf for specified tasks, such as handling bank accounts, signing contracts, or making medical decisions. For investors it matters because it determines who can buy, sell, or manage assets and make binding decisions during illness or absence—think of it as appointing a trusted agent to handle your financial and personal paperwork when you cannot. Keepers of these powers can affect ownership, voting, and access to funds.

FAQ

How much of 908 Devices Inc. (MASS) does ARCH Venture Fund VII beneficially own?

ARCH Venture Fund VII, L.P. beneficially owns 5,725,045 shares of 908 Devices Inc. Common Stock, representing 13.9% of the class based on 41,333,705 shares outstanding as of August 7, 2026.

What total percentage of 908 Devices Inc. (MASS) does Keith Crandell report owning?

Keith Crandell reports beneficial ownership of 5,824,877 shares of 908 Devices Inc., representing 14.1% of the Common Stock, assuming issuance of his vested and near-term vesting option shares on top of the reported outstanding shares.

What is the share count outstanding used in this 908 Devices Inc. (MASS) ownership filing?

The ownership percentages are calculated using 41,333,705 shares of 908 Devices Inc. Common Stock outstanding as of August 7, 2026, as reported by the company in its Form 10-Q filed on August 11, 2026.

Do the ARCH entities and managing directors share voting power over 908 Devices Inc. (MASS) shares?

Yes. The ARCH entities and managing directors report 5,725,045 shares with shared voting and dispositive power, reflecting their general-partner and managing-director roles over ARCH Venture Fund VII’s record holdings.

What additional equity in 908 Devices Inc. (MASS) does Keith Crandell hold besides fund-owned shares?

Keith Crandell holds 59,423 vested options, 39,374 fully vested restricted stock units, and 1,035 options vesting within sixty days, which are included in his reported beneficial ownership calculation.

Do the reporting persons fully acknowledge ownership of all 908 Devices Inc. (MASS) shares listed?

Each reporting person disclaims beneficial ownership of the reported 908 Devices Inc. shares, except for any shares that person holds of record, reflecting standard legal ownership disclaimers.

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Available on EDGAR 08/14/2026 - 04:09 PM Accepted by SEC EDGAR 08/14/2026 - 04:05 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 6)

908 Devices Inc.

(Name of Issuer)

Common Stock par value $0.001 per share

(Title of Class of Securities)

65443P102

(CUSIP Number)

06/30/2026

(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)

13.9 %

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)

13.9 %

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)

13.9 %

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 99,832.00
6	Shared Voting Power 5,725,045.00
7	Sole Dispositive Power 99,832.00
8	Shared Dispositive Power 5,725,045.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,824,877.00

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)

14.1 %

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)

13.9 %

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)

13.9 %

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 Road, 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 June 30, 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 June 30, 2026, Crandell is a holder of vested options to purchase 59,423 shares of Common Stock (the "Vested Option Shares"), 39,374 fully vested restricted stock units, and options to purchase 1,035 shares of Common Stock vesting within sixty days (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: 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 41,333,705 shares of Common Stock outstanding as of August 7, 2026, as reported by the Issuer in its Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 11, 2026, and in the case of Crandell, assumes the issuance of the Vested Option Shares and the Unvested Option Shares.
(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:	08/14/2026

Signature:	ARCH Venture Partners VII, LLC
Name/Title:	its General Partner
Date:	08/14/2026

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

ARCH Venture Partners VII, L.P.

Signature:	/s/ ARCH Venture Partners VII, LLC
Name/Title:	its General Partner
Date:	08/14/2026

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

ARCH Venture Partners VII, LLC

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director
Date:	08/14/2026

Keith Crandell

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Keith Crandell
Date:	08/14/2026

Clinton Bybee

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Clinton Bybee
Date:	08/14/2026

Robert Nelsen

Signature:	/s/ Mark McDonnell*
Name/Title:	Mark McDonnell, as Attorney-in-Fact for Robert Nelsen
Date:	08/14/2026

Comments accompanying signature: This Schedule 13G was executed by Mark McDonnell pursuant to Powers of Attorney included as Exhibit 2 to the Form 13G relating to the beneficial ownership of shares of 908 Devices Inc. by the Reporting Persons filed with the Securities and Exchange Commission on February 4, 2021, and incorporated herein in its entirety by reference.