[Form 4] 908 Devices Inc. Insider Trading Activity

Rhea-AI Filing Summary

908 Devices Inc. Chief Financial Officer Joseph H. Griffith IV reported planned stock sales under a Rule 10b5-1 trading plan. The filings show sales on 10/02/2025 and 10/03/2025 totaling 5,000 shares (708 shares and 4,292 shares) at weighted-average prices near $9.04 and $9.05, respectively. After these transactions the reporting person beneficially owned 92,930 shares. The footnotes state the sales were executed under the 10b5-1 plan and disclose price ranges for the multiple transactions.

Positive

• Sales executed under a Rule 10b5-1 plan, indicating pre-arranged compliance procedures
• Reporting person retained a substantial holding of 92,930 shares after the sales

Negative

• Reduction of position by 5,000 shares (708 and 4,292 shares) which lowers insider ownership
• Sales occurred at prices near $9.03–$9.09, signaling disposals at current market levels

Insights

Corporate Governance Expert

CFO used a Rule 10b5-1 plan to sell a small portion of holdings in early October 2025.

These sales were executed under a pre-arranged 10b5-1 plan, which provides an affirmative defense against insider trading claims when properly adopted. The filer reports weighted-average sale prices around $9.04 and $9.05.

The plan structure reduces legal risk from timing-based trading but does not necessarily indicate management view on valuation; monitor future Form 4 filings or any amendments to the plan for additional context within the next few months.

Equity Markets Analyst

Reported disposition reduced the CFO's stake by 5,000 shares, leaving 92,930 shares held.

The reported sales on 10/02/2025 and 10/03/2025 totaled 5,000 shares at weighted-average prices in a narrow band ($9.03–$9.09). The total reduction is specific and quantifiable.

Because the transactions were executed under a 10b5-1 plan, short-term market timing is less likely; watch for subsequent Form 4 entries or public disclosures over the next quarter that change the director/officer's ownership materially.

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).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Griffith Joseph H. IV

(Last) (First) (Middle)

C/O 908 DEVICES INC.

44 THIRD AVENUE

(Street)

BURLINGTON MA 01803

(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		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
10/02/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	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	10/02/2025		S(1)		708	D	$9.0364(2)	97,222	D
Common Stock	10/03/2025		S(1)		4,292	D	$9.0515(3)	92,930	D

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

Explanation of Responses:

1. Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $9.03 to $9.09,inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $9.03 to $9.07,inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

	/s/ Michael S. Turner, as Attorney-in-Fact	10/06/2025
	** Signature of Reporting Person	Date
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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did 908 Devices (MASS) CFO sell and when?

The CFO sold 5,000 shares in two transactions on 10/02/2025 and 10/03/2025 under a Rule 10b5-1 plan.

At what prices were the MASS shares sold?

The filings report weighted-average prices near $9.04 and $9.05, with transaction price ranges between $9.03 and $9.09.

How many MASS shares does the reporting person own after the transactions?

Following the reported sales the reporting person beneficially owned 92,930 shares.

Were the sales discretionary trades or pre-planned?

The sales were executed pursuant to a pre-arranged Rule 10b5-1 trading plan, as stated in the filing.

Who filed the Form 4 for these transactions?

The Form 4 was filed by Joseph H. Griffith IV, Chief Financial Officer of 908 Devices Inc.