MASS SVP exercises options, sells 2,693 shares

908 Devices Inc. senior vice president Kevin J. McCallion exercised stock options for 2,693 shares of common stock at $1.05 per share and sold the same 2,693 shares at a weighted average price of $7.01 per share.

Rhea-AI Filing Summary

908 Devices Inc. senior vice president Kevin J. McCallion exercised stock options for 2,693 shares of common stock at $1.05 per share and sold the same 2,693 shares at a weighted average price of $7.01 per share. The sale was made pursuant to a Rule 10b5-1 trading plan adopted on December 9, 2025, indicating it was pre‑scheduled. Following the transactions, he directly holds 44,925 shares of common stock, and the underlying option grant is now fully exercised.

Insider Trade Summary 10b5-1

Exercise and Sale: 2,693 shares ($16K approx. pre-tax spread)

Exercise and Sale 3 txns

Insider McCallion Kevin J.

Role SVP, Products and Production

Sold 2,693 shs ($19K)

Approx. gross sale proceeds $19K

Approx. exercise cost $3K

Approx. pre-tax spread $16K

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy)	2,693	$0.00	$0.00
Exercise	Common Stock	2,693	$1.05	$3K
Sale	Common Stock	2,693	$7.01	$19K

Holdings After Transaction: Stock Option (right to buy) — 0 contracts (Direct); Common Stock — 44,925 shares (Direct)

Footnotes (4)

1. F1. This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 9, 2025.
2. F2. 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 $7.03 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. F3. The shares underlying the option are fully vested and immediately exercisable.
4. F4. Due to a scrivener's error on the Form 3, the number of stock options beneficially owned by the Reporting Person pursuant to this grant was understated by 7. Following this transaction, the entire option grant has been exercised.

Key Figures

Options exercised: 2,693 shares Option exercise price: $1.05 per share Shares sold: 2,693 shares +3 more

6 metrics

Options exercised 2,693 shares Stock options converted to common stock on April 10, 2026

Option exercise price $1.05 per share Exercise price for 2,693 stock options

Shares sold 2,693 shares Common stock sold in open-market transactions

Weighted average sale price $7.01 per share Sales between $7.00 and $7.03 on April 10, 2026

Shares owned after transactions 44,925 shares Direct common stock holdings following the Form 4 transactions

Option expiration date August 27, 2030 Original expiration date of exercised stock option grant

Key Terms

Rule 10b5-1 trading plan, weighted average price, Stock Option (right to buy), Exercise or conversion of derivative security, +1 more

5 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.

weighted average price financial

"The price reported in Column 4 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.

Stock Option (right to buy) financial

"security_title: Stock Option (right to buy)"

Exercise or conversion of derivative security financial

"transaction_code_description: Exercise or conversion of derivative security"

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.

FAQ

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

What did MASS executive Kevin J. McCallion report in this Form 4?

Kevin J. McCallion reported exercising stock options for 2,693 shares of 908 Devices common stock at $1.05 per share and selling 2,693 shares at a weighted average of $7.01. After these transactions, he directly holds 44,925 shares.

Was the MASS insider sale by Kevin J. McCallion pre-planned under Rule 10b5-1?

Yes. The filing states the sale was executed under a Rule 10b5-1 trading plan adopted on December 9, 2025. Such plans allow insiders to schedule trades in advance, reducing the significance of trade timing as a signal.

How many MASS shares did Kevin J. McCallion sell and at what price?

He sold 2,693 shares of 908 Devices common stock at a weighted average price of $7.01 per share. A footnote explains these shares were sold in multiple trades between $7.00 and $7.03 per share inclusive.

What stock options did Kevin J. McCallion exercise in this MASS Form 4?

He exercised stock options covering 2,693 shares of 908 Devices common stock at an exercise price of $1.05 per share. A footnote notes the option was fully vested and immediately exercisable and that, after this transaction, the entire option grant has been exercised.

How many MASS shares does Kevin J. McCallion own after these transactions?

After exercising options and selling shares, Kevin J. McCallion directly owns 44,925 shares of 908 Devices common stock. This figure reflects his holdings immediately following the reported exercise and open-market sale on April 10, 2026.

What does the weighted average price mean in this MASS insider sale?

The weighted average price of $7.01 per share reflects multiple trades between $7.00 and $7.03. The filing notes the insider will provide detailed share counts at each price upon request to the company, shareholders, or regulators.

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

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Accepted by SEC EDGAR 04/14/2026 - 04:00 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^*

McCallion Kevin J.

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, Products and Production

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/10/2026

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	04/10/2026		M(1)		2,693	A	$1.05	47,618	D
Common Stock	04/10/2026		S(1)		2,693	D	$7.01(2)	44,925	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
Stock Option (right to buy)	$1.05	04/10/2026		M(1)			2,693	(3)	08/27/2030	Common Stock	2,693	$0	0(4)	D

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.

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 $7.03 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.

4. Due to a scrivener's error on the Form 3, the number of stock options beneficially owned by the Reporting Person pursuant to this grant was understated by 7. Following this transaction, the entire option grant has been exercised.

	/s/ Mark S. Levine, Attorney-in-Fact	04/14/2026
	** 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)