ARK Investment Management (MASS) reports 2.0M-share, 5.32% holding in 908 Devices

Rhea-AI Filing Summary

908 Devices Inc. common stock is reported as being beneficially owned by ARK Investment Management LLC and its CEO/CIO, Catherine D. Wood. They report ownership of 2,027,920 shares of common stock, representing 5.32% of the outstanding class.

ARK has sole voting and dispositive power over the 2,027,920 shares, while Catherine D. Wood reports shared voting and dispositive power over the same shares and no sole authority. The filing notes that no ARK client exceeds a 5% interest in these securities other than ARK Genomic Revolution ETF.

Key Figures

Shares beneficially owned: 2,027,920 shares Percent of class: 5.32% Sole voting power (ARK): 2,027,920 shares +3 more

6 metrics

Shares beneficially owned 2,027,920 shares Common stock of 908 Devices Inc. beneficially owned by ARK and Catherine D. Wood

Percent of class 5.32% Percentage of 908 Devices Inc. common stock class reported as beneficially owned

Sole voting power (ARK) 2,027,920 shares Shares over which ARK has sole power to vote or direct the vote

Shared voting power (C. Wood) 2,027,920 shares Shares over which Catherine D. Wood has shared power to vote or direct the vote

Sole dispositive power (ARK) 2,027,920 shares Shares over which ARK has sole power to dispose or direct disposition

Shared dispositive power (C. Wood) 2,027,920 shares Shares over which Catherine D. Wood has shared power to dispose or direct disposition

Key Terms

beneficially owned, sole voting power, shared dispositive power, percent of class, +1 more

5 terms

beneficially owned financial

"Amount beneficially owned: ARK and Catherine D. Wood: 2,027,920"

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.

sole voting power financial

"Sole Voting Power 2,027,920.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

shared dispositive power financial

"Shared Dispositive Power 2,027,920.00"

percent of class financial

"Percent of class: ARK and Catherine D. Wood: 5.32"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

Schedule 13G/A regulatory

"Form type: SCHEDULE 13G/A"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

FAQ

How many 908 Devices Inc. (MASS) shares do ARK and Catherine Wood report owning?

ARK Investment Management LLC and Catherine D. Wood report beneficial ownership of 2,027,920 shares of 908 Devices Inc. common stock, as disclosed in the Schedule 13G/A filing.

What percentage of 908 Devices Inc. (MASS) does ARK Investment Management LLC own?

ARK Investment Management LLC and Catherine D. Wood report owning 5.32% of 908 Devices Inc. common stock, based on 2,027,920 shares beneficially owned.

Who has voting and dispositive power over MASS shares reported by ARK?

ARK reports sole voting and sole dispositive power over 2,027,920 shares. Catherine D. Wood reports shared voting and shared dispositive power over the same 2,027,920 shares and no sole power.

Does any ARK client hold more than 5% of 908 Devices Inc. (MASS)?

The filing states that no ARK client has over 5% interest in the disclosed securities except ARK Genomic Revolution ETF, a series of a Delaware statutory trust.

Who are the reporting persons in the MASS Schedule 13G/A filing?

The reporting persons are ARK Investment Management LLC and Catherine D. Wood, with ARK organized in Delaware and Wood a citizen of the United States.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/14/2026 - 03:00 PM Accepted by SEC EDGAR 08/14/2026 - 02:59 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. 9)

908 Devices Inc.

(Name of Issuer)

Common Stock

(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

ARK Investment Management 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 2,027,920.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,027,920.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,027,920.00

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)

5.32 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP Number(s): 65443P102

1

Names of Reporting Persons

Catherine D. Wood

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 2,027,920.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,027,920.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,027,920.00

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)

5.32 %

12

Type of Reporting Person (See Instructions)

HC, 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: (i) ARK Investment Management LLC ("ARK") (ii) Catherine D. Wood
(b)	Address or principal business office or, if none, residence: ARK and Catherine D. Wood: 200 Central Avenue, St. Petersburg, FL 33701
(c)	Citizenship: (i) ARK: Delaware (ii) Catherine D. Wood: United States
(d)	Title of class of securities: Common Stock
(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: ARK and Catherine D. Wood: 2,027,920
(b)	Percent of class: ARK and Catherine D. Wood: 5.32
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: (i) ARK: 2,027,920 (ii) Catherine D. Wood: 0
	(ii) Shared power to vote or to direct the vote: (i) ARK: 0 (ii) Catherine D. Wood: 2,027,920
	(iii) Sole power to dispose or to direct the disposition of: (i) ARK: 2,027,920 (ii) Catherine D. Wood: 0
	(iv) Shared power to dispose or to direct the disposition of: (i) ARK: 0 (ii) Catherine D. Wood: 2,027,920
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.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. No client of ARK Investment Management LLC currently has an interest in the securities reported herein in excess of 5 percent except ARK Genomic Revolution ETF, a series of a Delaware statutory trust.
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:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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.

ARK Investment Management LLC

Signature:	/s/ Kellen Carter
Name/Title:	Kellen Carter, Chief Compliance Officer
Date:	08/14/2026

Catherine D. Wood

Signature:	/s/ Catherine D. Wood
Name/Title:	Catherine D. Wood, Chief Executive Officer, Chief Investment Officer
Date:	08/14/2026