908 Devices director Brown sells 30,000 shares

Q: How many MASS shares did 908 Devices director Christopher D. Brown sell, and at what price?

Christopher D. Brown sold 30,000 shares at a weighted average price of $11.89 per share. The reported sale prices ranged from $11.75 to $12.12 inclusive.

Q: How many options did the MASS director exercise, and at what exercise price?

He exercised options covering 60,000 common shares at $1.75 per share on October 7, 2026. The options were fully vested and immediately exercisable.

Q: Was the MASS share sale made under a Rule 10b5-1 plan?

Yes. The 30,000-share sale was made under a Rule 10b5-1 trading plan adopted November 24, 2025.

The 30,000-share sale was made under a Rule 10b5-1 trading plan adopted November 24, 2025.

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Filing Sentiment

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Form Type

Rhea-AI Filing Summary

On October 7, 2026, 908 Devices Inc. director Christopher D. Brown exercised options to acquire 60,000 common shares at $1.75 per share. He sold 30,000 common shares at a weighted average price of $11.89 per share, with reported sale prices ranging from $11.75 to $12.12. The option transaction reports 54,318 shares following the exercise; the options were fully vested and immediately exercisable, and expire June 22, 2027.

Insider Trade Summary 10b5-1

Exercise and sale activity reported; no spread calculated

Exercise and Sale 3 txns

Insider Brown Christopher D.

Role Director

Sold 30,000 shs ($357K)

Approx. gross sale proceeds $357K

Approx. exercise cost $105K

Type	Security	Shares	Price	Value
Exercise	Stock Option (option to buy) ^F3	60,000	$0.00	$0.00
Sale	Common Stock ^{F1, F2}	30,000	$11.89	$357K
Exercise	Common Stock	60,000	$1.75	$105K

Holdings After Transaction: Stock Option (option to buy) — 54,318 contracts (Direct); Common Stock — 805,559 shares (Direct)

Footnotes (3)

F1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 24, 2025.
F2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.75 to $12.12 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 range set forth in this footnote.
F3. The shares underlying the option are fully vested and immediately exercisable.

Key Figures

Common shares acquired on option exercise: 60,000 shares Option exercise price: $1.75 per share Common shares sold: 30,000 shares +4 more

7 metrics

Common shares acquired on option exercise 60,000 shares October 7, 2026

Option exercise price $1.75 per share Options exercised October 7, 2026

Common shares sold 30,000 shares October 7, 2026

Weighted average sale price $11.89 per share Sale on October 7, 2026

Reported sale price range $11.75–$12.12 per share Sale on October 7, 2026

Shares following option transaction 54,318 shares Reported following the October 7, 2026 transaction

Option expiration date June 22, 2027 Exercised option

Key Terms

Rule 10b5-1 trading plan, weighted average price, fully vested, immediately exercisable

4 terms

Rule 10b5-1 trading plan regulatory

"pursuant to a Rule 10b5-1 trading plan"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported is a weighted average price"

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

fully vested financial

"The shares underlying the option are fully vested"

immediately exercisable financial

"fully vested and immediately exercisable"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many MASS shares did 908 Devices director Christopher D. Brown sell, and at what price?

Christopher D. Brown sold 30,000 shares at a weighted average price of $11.89 per share. The reported sale prices ranged from $11.75 to $12.12 inclusive.

How many options did the MASS director exercise, and at what exercise price?

He exercised options covering 60,000 common shares at $1.75 per share on October 7, 2026. The options were fully vested and immediately exercisable.

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

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 10/09/2026 - 04:15 PM EDT Accepted by SEC EDGAR 10/09/2026 - 04:15 PM EDT

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).

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^*

Brown Christopher D.

(Last)

(First)

(Middle)

C/O 908 DEVICES INC.

44 3RD AVENUE

(Street)

BURLINGTON

MASSACHUSETTS

01803

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
908 Devices Inc. [ MASS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/07/2026

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

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	10/07/2026		S⁽¹⁾		30,000	D	$11.89⁽²⁾	745,559	D
Common Stock	10/07/2026		M		60,000	A	$1.75	805,559	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (option to buy)	$1.75	10/07/2026		M			60,000	⁽³⁾	06/22/2027	Common Stock	60,000	$0	54,318	D

Explanation of Responses:

1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 24, 2025.

2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.75 to $12.12 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, 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 range set forth in this footnote.

3. The shares underlying the option are fully vested and immediately exercisable.

	/s/ Mark S. Levine, Attorney-in-Fact	10/09/2026
	** 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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR