908 Devices SVP sells shares to cover PSU taxes

908 Devices Inc. SVP John Kenneweg reported a routine equity compensation event involving vested performance stock units (PSUs) and a related tax sale.

Rhea-AI Filing Summary

908 Devices Inc. SVP John Kenneweg reported a routine equity compensation event involving vested performance stock units (PSUs) and a related tax sale. On May 1, 2026, 26,042 PSUs vested and were converted into 26,042 shares of Common Stock. To cover tax withholding obligations from this vesting, 7,787 shares of Common Stock were sold in an open-market “sell to cover” transaction at $6.83 per share, a sale mandated by the company’s election and described as non-discretionary for the insider. Following these transactions, Kenneweg directly holds 76,039 shares of Common Stock, and all of the reported PSUs have been fully settled.

Insider Trade Summary

Exercise and sale activity reported; no spread calculated

Exercise and Sale 3 txns

Insider Kenneweg John

Role SVP, Sales & Product Marketing

Sold 7,787 shs ($53K)

Approx. gross sale proceeds $53K

Approx. exercise cost $0.00

Type	Security	Shares	Price	Value
Exercise	Performance Stock Units	26,042	$0.00	$0.00
Exercise	Common Stock	26,042	$0.00	$0.00
Sale	Common Stock	7,787	$6.83	$53K

Holdings After Transaction: Performance Stock Units — 0 contracts (Direct); Common Stock — 76,039 shares (Direct)

Footnotes (3)

1. F1. Each performance stock unit ("PSU") represents a contingent right to receive one share of Common Stock, par value $0.001, when vested.
2. F2. The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of PSUs. The sale is mandated by the Issuer's election to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.
3. F3. The PSUs vested, in accordance with their terms, on May 1, 2026. The PSUs had no expiration date.

Key Figures

Tax-related shares sold: 7,787 shares at $6.83 PSUs vested and converted: 26,042 units/shares Shares held after transactions: 76,039 shares +2 more

5 metrics

Tax-related shares sold 7,787 shares at $6.83 Open-market sale to cover tax withholding on May 1, 2026

PSUs vested and converted 26,042 units/shares Performance stock units vesting and settlement on May 1, 2026

Shares held after transactions 76,039 shares Direct common stock ownership following Form 4 transactions

Net buy/sell shares -7,787 shares Net effect of reported buy/sell activity in this filing

Remaining derivative PSUs 0 units All reported PSUs settled into common stock after vesting

Key Terms

performance stock unit, sell to cover, tax withholding obligations, derivative security, +1 more

5 terms

performance stock unit financial

"Each performance stock unit ("PSU") represents a contingent right to receive one share of Common Stock..."

A performance stock unit is a type of reward companies give to employees, usually managers, that depends on how well the company performs over time. If the company hits specific goals, the employee earns shares of stock, like earning a prize for reaching certain levels in a game. It motivates employees to work hard because their rewards are tied to the company's success.

sell to cover financial

"tax withholding obligations to be funded by a "sell to cover" transaction..."

Sell to cover is when a person who receives company stock through options or awards sells just enough shares immediately to pay required taxes, exercise costs, or fees, keeping the rest. Think of it like cashing part of a bonus to cover the tax bill so you can keep the remainder. For investors, it can create predictable small selling pressure and slightly change the number of shares actually held by insiders without increasing long‑term dilution.

tax withholding obligations financial

"shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting..."

derivative security financial

"Exercise or conversion of derivative security"

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

vesting and settlement financial

"in connection with the vesting and settlement of PSUs"

FAQ

What insider transactions did 908 Devices (MASS) report for John Kenneweg?

908 Devices SVP John Kenneweg had 26,042 performance stock units vest and convert into 26,042 common shares. To cover related tax withholding, 7,787 shares were sold in a mandated open-market “sell to cover” transaction at $6.83 per share.

Was the 908 Devices (MASS) insider share sale by John Kenneweg discretionary?

The sale was not discretionary. Footnotes state the 7,787 shares were sold solely to satisfy tax withholding obligations from PSU vesting under a company “sell to cover” election, meaning the transaction was required rather than a voluntary open-market sale decision.

How many 908 Devices (MASS) shares does John Kenneweg hold after this Form 4?

After the reported transactions, John Kenneweg directly owns 76,039 shares of 908 Devices common stock. This reflects his holdings after 26,042 PSUs vested into shares and 7,787 shares were sold to cover associated tax withholding obligations.

What are performance stock units (PSUs) in the 908 Devices (MASS) filing?

In this filing, each performance stock unit represents a contingent right to receive one share of 908 Devices common stock upon vesting. On May 1, 2026, 26,042 PSUs vested under their terms and were settled into an equal number of common shares.

How large was the tax-related share sale for 908 Devices (MASS) SVP Kenneweg?

The tax-related sale involved 7,787 shares of 908 Devices common stock at $6.83 per share. According to the footnotes, this “sell to cover” transaction was executed to fund withholding taxes triggered by the vesting and settlement of performance stock units.

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

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Accepted by SEC EDGAR 05/04/2026 - 04:30 PM 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).

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^*

Kenneweg John

(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, Sales & Product Marketing

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/01/2026

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	05/01/2026		M		26,042	A	(1)	83,826	D
Common Stock	05/01/2026		S(2)		7,787	D	$6.83	76,039	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
Performance Stock Units	(1)	05/01/2026		M			26,042	(3)	(3)	Common Stock	26,042	$0	0	D

Explanation of Responses:

1. Each performance stock unit ("PSU") represents a contingent right to receive one share of Common Stock, par value $0.001, when vested.

2. The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of PSUs. The sale is mandated by the Issuer's election to require the satisfaction of tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

3. The PSUs vested, in accordance with their terms, on May 1, 2026. The PSUs had no expiration date.

	/s/ Mark S. Levine, Attorney-in-Fact	05/04/2026
	** 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.
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* Form 4: SEC 1474 (03-26)