908 Devices Inc. (MASS) director sells 20,000 shares in planned trade

Rhea-AI Filing Summary

908 Devices Inc. director Christopher D. Brown sold shares in a planned transaction. On May 6, 2026, he completed an open-market sale of 20,000 shares of common stock at a weighted average price of $7.23 per share, under a pre-arranged Rule 10b5-1 trading plan adopted on November 24, 2025.

After this sale, Brown directly holds 925,559 shares of 908 Devices common stock. The shares were sold in multiple trades at prices ranging from $7.00 to $7.49 per share.

Insider Trade Summary 10b5-1

Net Seller: 20,000 shares ($144,600)

Net Sell 1 txn

Insider Brown Christopher D.

Role null

Sold 20,000 shs ($145K)

Type	Security	Shares	Price	Value
Sale	Common Stock	20,000	$7.23	$145K

Holdings After Transaction: Common Stock — 925,559 shares (Direct, null)

Footnotes (1)

1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 24, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.00 to $7.49 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.

Key Figures

Shares sold: 20,000 shares Average sale price: $7.23 per share Post-transaction holdings: 925,559 shares +1 more

4 metrics

Shares sold 20,000 shares Open-market sale on May 6, 2026

Average sale price $7.23 per share Weighted average across multiple trades

Post-transaction holdings 925,559 shares Directly held after the sale

Sale price range $7.00–$7.49 per share Range of prices for individual trades

Key Terms

Rule 10b5-1 trading plan, weighted average price, open-market sale, Form 4

4 terms

Rule 10b5-1 trading plan regulatory

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

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 in Column 4 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.

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.

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 →

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^*

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)
05/06/2026

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/06/2026		S(1)		20,000	D	$7.23(2)	925,559	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)
				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 November 24, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.00 to $7.49 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.

	/s/ Mark S. Levine, Attorney-in-Fact	05/07/2026
	** 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)

FAQ

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

908 Devices reported that director Christopher D. Brown sold 20,000 shares of common stock. The sale was an open-market transaction executed under a Rule 10b5-1 trading plan, providing a structured, pre-arranged schedule for selling shares over time.

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

Christopher D. Brown sold 20,000 908 Devices shares at a weighted average price of $7.23. The trades occurred in multiple transactions, with individual sale prices ranging from $7.00 to $7.49 per share, as disclosed in the Form 4 footnotes.

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

Following the reported sale, Christopher D. Brown directly holds 925,559 shares of 908 Devices common stock. This post-transaction holding figure comes from the Form 4 and reflects his remaining direct ownership after disposing of 20,000 shares in the open market.

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

Yes. The Form 4 states the transaction was made under a Rule 10b5-1 trading plan adopted on November 24, 2025. Such plans pre-schedule trades, helping separate routine portfolio management from discretionary, market-timing decisions by insiders.

What does the weighted average price disclosure mean in the 908 Devices (MASS) Form 4?

The Form 4 reports a weighted average sale price of $7.23 for the 20,000 shares. Footnotes explain the shares were sold in multiple trades between $7.00 and $7.49, and Brown can provide detailed trade-by-trade pricing information upon request to interested parties.