908 Devices (MASS) SVP McCallion sells shares under 10b5-1 plan

Rhea-AI Filing Summary

908 Devices Inc. senior vice president Kevin J. McCallion reported an open-market sale of 7 shares of common stock at $7.00 per share on March 2, 2026. After this trade, he directly holds 44,918 common shares. The sale was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 9, 2025.

Insider Trade Summary

Net Seller: 7 shares ($49)

Net Sell 1 txn

Insider McCallion Kevin J.

Role SVP, Products and Production

Sold 7 shs ($49.00)

Type	Security	Shares	Price	Value
Sale	Common Stock	7	$7.00	$49.00

Holdings After Transaction: Common Stock — 44,918 shares (Direct)

Footnotes (1)

1. [object Object]

Form 4 Insider Transactions: What Each Field Means →

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^*

McCallion Kevin J.

(Last) (First) (Middle)

C/O 908 DEVICES INC.

44 3RD 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)
	SVP, Products and Production

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

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	03/02/2026		S(1)		7	D	$7	44,918	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. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 9, 2025.

	/s/ Mark S. Levine, Attorney-in-Fact	03/04/2026
	** 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 insider transaction did 908 Devices (MASS) report for Kevin J. McCallion?

Kevin J. McCallion reported selling 7 shares of 908 Devices common stock. The transaction was an open-market sale at $7.00 per share, executed under a Rule 10b5-1 trading plan adopted on December 9, 2025.

At what price did the 908 Devices (MASS) insider shares sell?

The reported 7 shares of 908 Devices common stock sold at $7.00 per share. This reflects an open-market transaction and was carried out pursuant to a previously adopted Rule 10b5-1 trading plan.

How many 908 Devices (MASS) shares does Kevin J. McCallion hold after the sale?

After the reported sale, Kevin J. McCallion directly holds 44,918 shares of 908 Devices common stock. This post-transaction balance reflects the reduction of 7 shares from his prior direct holdings.

Was the 908 Devices (MASS) insider sale under a Rule 10b5-1 plan?

Yes, the sale was made under a Rule 10b5-1 trading plan. The footnote specifies the plan was adopted by Kevin J. McCallion on December 9, 2025, providing a pre-arranged framework for trades.

What role does Kevin J. McCallion hold at 908 Devices (MASS)?

Kevin J. McCallion serves as Senior Vice President, Products and Production at 908 Devices. His Form 4 filing reflects a personal open-market sale of common stock executed under a Rule 10b5-1 trading plan.