908 Devices (NASDAQ: MASS) director sells 30K shares under 10b5-1 plan

Filing Impact

(Moderate)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

908 Devices Inc. director Christopher D. Brown sold 30,000 shares of Common Stock in an open-market transaction at $9.00 per share. After the sale on May 28, 2026, he directly held 895,559 shares of the company’s stock. The trade was executed under a pre-arranged Rule 10b5-1 trading plan adopted on November 24, 2025, indicating the sale was scheduled in advance rather than timed discretionarily.

Insider Trade Summary 10b5-1

Net Seller: 30,000 shares ($270,000)

Net Sell 1 txn

Insider Brown Christopher D.

Role null

Sold 30,000 shs ($270K)

Type	Security	Shares	Price	Value
Sale	Common Stock	30,000	$9.00	$270K

Holdings After Transaction: Common Stock — 895,559 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares sold: 30,000 shares Sale price: $9.00 per share Shares held after: 895,559 shares +2 more

5 metrics

Shares sold 30,000 shares Open-market sale of Common Stock on May 28, 2026

Sale price $9.00 per share Price for 30,000-share open-market sale

Shares held after 895,559 shares Direct ownership after reported transaction

Rule 10b5-1 plan adoption date November 24, 2025 Date Brown adopted the trading plan used for this sale

Transaction code S Sale in open market or private transaction

Key Terms

Rule 10b5-1 trading plan, open-market sale, Common Stock, Form 4

4 terms

Rule 10b5-1 trading plan regulatory

"This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person"

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.

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Common Stock financial

"security_title": "Common Stock""

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

Form 4 regulatory

"INSIDER FILING DATA (Form 4):"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

Form 4 Insider Transactions: What Each Field Means →

05/29/2026 - 04:15 PM

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)
05/28/2026

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	05/28/2026		S⁽¹⁾		30,000	D	$9	895,559	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)

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.

	/s/ Mark S. Levine, Attorney-in-Fact	05/29/2026
	** 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

FAQ

What insider transaction did 908 Devices Inc. (MASS) report for Christopher D. Brown?

908 Devices reported that director Christopher D. Brown sold 30,000 shares of Common Stock at $9.00 per share. The transaction was an open-market sale and was carried out under a pre-arranged Rule 10b5-1 trading plan adopted in November 2025.

How many 908 Devices (MASS) shares does Christopher D. Brown hold after this sale?

After the reported sale, Christopher D. Brown directly holds 895,559 shares of 908 Devices Common Stock. This figure reflects his position following the 30,000-share open-market sale disclosed, giving investors context for the scale of the transaction relative to his remaining stake.

At what price did Christopher D. Brown sell his 908 Devices (MASS) shares?

Christopher D. Brown sold the 30,000 908 Devices shares at $9.00 per share. This price applies to the non-derivative Common Stock transaction reported and helps investors gauge the dollar value of the sale alongside his remaining 895,559-share holding.

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

Yes. The filing states the sale was made pursuant to a Rule 10b5-1 trading plan adopted on November 24, 2025. Such plans pre-schedule trades, indicating this 30,000-share sale was planned in advance rather than being a spontaneous market-timing decision.

What type of security did Christopher D. Brown sell in the 908 Devices (MASS) Form 4?

The Form 4 shows that Christopher D. Brown sold non-derivative Common Stock of 908 Devices. The transaction involved 30,000 shares in an open-market sale at $9.00 per share, and no derivative securities, such as options or warrants, were reported in this filing.