908 Devices Inc. — Director's Dealing 2026

Feb 3, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: 908 Devices Inc. (MASS)
CIK: 0001555279
Period of Report: 2026-02-01

Reporting Person: Knopp Kevin J. (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-01	Common Stock	M	11255	—	Acquired	733988	Direct
2026-02-01	Common Stock	M	13449	—	Acquired	747437	Direct
2026-02-01	Common Stock	M	17007	—	Acquired	764444	Direct
2026-02-01	Common Stock	M	66288	—	Acquired	830732	Direct
2026-02-02	Common Stock	S	34764	$6.18	Disposed	795968	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-01	Restricted Stock Units	$	M	11255	Disposed		Common Stock (11255)	Direct
2026-02-01	Restricted Stock Units	$	M	13449	Disposed		Common Stock (13449)	Direct
2026-02-01	Restricted Stock Units	$	M	17007	Disposed		Common Stock (17007)	Direct
2026-02-01	Restricted Stock Units	$	M	66288	Disposed		Common Stock (66288)	Direct
2026-02-02	Restricted Stock Units	$	A	205978	Acquired		Common Stock (205978)	Direct
2026-02-02	Stock Option (option to buy)	$6.19	A	90043	Acquired	2036-02-01	Common Stock (90043)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	541223	Indirect

Footnotes

F1: Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date.

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 RSUs. 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.

F3: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.105 to $6.32, inclusive. The reporting person undertakes to provide to Issuer, any security holder of 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 ranges set forth in this footnote.

F4: The shares are owned directly by The Kevin J. Knopp Irrevocable Trust of 2018. The reporting person's brother-in-law is the trustee of The Kevin J. Knopp Irrevocable Trust of 2018 and has sole voting and dispositive control with respect to all securities held by such trust. The reporting person may be deemed to be the beneficial owner of the securities held by The Kevin J. Knopp Irrevocable Trust of 2018.

F5: These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2022, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date.

F6: These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2023, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date.

F7: These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2024, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date.

F8: The RSUs shall vest one-third on February 1, 2026, with the remaining two-thirds vesting in two substantially equal annual installments at the two anniversary dates following February 1, 2026, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date.

F9: The RSUs shall vest one-third on February 1, 2027, with the remaining two-thirds vesting in two substantially equal annual installments at the two anniversary dates following February 1, 2027, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date.

F10: One-third of the shares underlying the option become vested and exercisable on February 1, 2027, and the remaining two-thirds of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 24 months following February 1, 2027, subject to the reporting person's continued service through the applicable vesting date.