908 Devices director sells 9,900 shares in plan trade

908 Devices Inc. director Christopher D. Brown reported an open-market sale of 9,900 shares of common stock at a weighted average price of $9.04 per share.

Rhea-AI Filing Summary

908 Devices Inc. director Christopher D. Brown reported an open-market sale of 9,900 shares of common stock at a weighted average price of $9.04 per share. The trades were executed at prices ranging from $9.00 to $9.08.

These transactions were carried out under a pre-arranged Rule 10b5-1 trading plan adopted on November 24, 2025. After the sale, Brown directly holds 865,559 shares of 908 Devices common stock, indicating he retains a substantial equity position in the company.

Insider Trade Summary 10b5-1

Net Seller: 9,900 shares

Net Sell 1 txn

Insider Brown Christopher D.

Role Director

Sold 9,900 shs ($89K)

Type	Security	Shares	Price	Value
Sale	Common Stock	9,900	$9.04	$89K

Holdings After Transaction: Common Stock — 865,559 shares (Direct)

Footnotes (2)

1. F1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 24, 2025.
2. F2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $9.00 to $9.08 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: 9,900 shares Weighted average sale price: $9.04 per share Sale price range: $9.00–$9.08 per share +3 more

6 metrics

Shares sold 9,900 shares Open-market sale of common stock

Weighted average sale price $9.04 per share Sale of 9,900 shares

Sale price range $9.00–$9.08 per share Multiple transactions on same date

Shares owned after sale 865,559 shares Direct holdings following transaction

Trading plan adoption date November 24, 2025 Rule 10b5-1 plan governing this sale

Transaction date June 23, 2026 Date of open-market sale

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 by the Reporting Person on November 24, 2025."

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. These shares were sold in multiple transactions..."

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.

FAQ

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

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

Christopher D. Brown reported selling 9,900 shares of 908 Devices common stock. The sale was an open-market transaction executed under a pre-arranged Rule 10b5-1 trading plan, providing a structured approach to gradually reducing a small portion of his holdings.

At what price did Christopher D. Brown sell MASS shares in this Form 4?

Brown sold 9,900 908 Devices shares at a weighted average price of $9.04. Individual sale prices ranged from $9.00 to $9.08 per share, reflecting multiple trades grouped into one reported transaction in the Form 4 filing’s pricing footnote.

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

After the reported sale, Brown directly holds 865,559 shares of 908 Devices common stock. This indicates the 9,900 shares sold represent only a small fraction of his overall position, and he continues to maintain a large equity stake in the company.

Was Christopher D. Brown’s MASS stock sale made under a Rule 10b5-1 plan?

Yes. The Form 4 specifies the transaction was made pursuant to a Rule 10b5-1 trading plan adopted on November 24, 2025. Such plans pre-schedule trades, helping separate routine portfolio management from discretionary, potentially market-timing-driven transactions.

What does the weighted average price disclosure mean in this MASS Form 4?

The weighted average price of $9.04 indicates Brown’s 9,900 shares were sold in multiple trades between $9.00 and $9.08. The average consolidates those executions, and he offers to provide detailed per-trade information to the issuer, shareholders, or SEC staff upon request.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 06/25/2026 - 05:15 PM EDT Learn about SEC filing dates

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)
06/23/2026

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	06/23/2026		S(1)		9,900	D	$9.04(2)	865,559	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 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $9.00 to $9.08 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	06/25/2026
	** 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)