E. Kevin Hrusovsky - 10 Jun 2026 Form 4 Insider Report for 908 Devices Inc. (MASS)

Reporting relationship: Director
Issuer ticker: MASS
Reported as of: 10 Jun 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 12 Jun 2026, 16:49:58 UTC
Prior SEC filing: 13 Jun 2025
Source filing: View source filing
Reporting owner signature: /s/ Mark S. Levine, Attorney-in-Fact

Key filing fact

E. Kevin Hrusovsky filed Form 4 for 908 Devices Inc. (MASS) on 12 Jun 2026.

Key facts

This page summarizes E. Kevin Hrusovsky's Form 4 filing for 908 Devices Inc. (MASS).
4 reported transactions and 3 derivative rows are listed below.
Accepted by SEC: 12 Jun 2026, 16:49.

Change

Previous filing in this sequence was filed on 13 Jun 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001252546 Primary reporting owner

HRUSOVSKY E KEVIN

Relationship: Director
Address: C/O 908 DEVICES INC., 44 THIRD AVENUE, BURLINGTON
Signature: /s/ Mark S. Levine, Attorney-in-Fact
Signature date: 12 Jun 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MASS transaction

Common Stock

Options Exercise

Transaction value
Shares: +14,083
Change %: +9.3%
Price
Shares after: 165,390
Date: 10 Jun 2026
Ownership: Direct
Footnotes: F1

MASS holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 329,675
Date: 10 Jun 2026
Ownership: See footnote
Footnotes: F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MASS transaction Derivative

Restricted Stock Units

Options Exercise

Transaction value
Shares: -14,083
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 10 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 14,083
Exercise price
Footnotes: F1, F3

MASS transaction Derivative

Restricted Stock Units

Award

Transaction value
Shares: +13,656
Change %
Price: $0.000000^*
Shares after: 13,656
Date: 11 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 13,656
Exercise price
Footnotes: F1, F4

MASS transaction Derivative

Stock Option (option to buy)

Award

Transaction value
Shares: +6,209
Change %
Price: $0.000000^*
Shares after: 6,209
Date: 11 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 6,209
Exercise price: $8.22
Footnotes: F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 5 footnotes

Footnote F1

Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of Common Stock, par value $0.001, when vested.

Footnote F2

The securities are owned directly by the E. Kevin Hrusovsky 2012 Irrevocable Trust. The reporting person's spouse and children are trustees of E. Kevin Hrusovsky 2012 Irrevocable Trust and have joint voting and dispositive control with respect to all securities held by E. Kevin Hrusovsky 2012 Irrevocable Trust and the reporting person may be deemed to be the beneficial owner of the securities held by E. Kevin Hrusovsky 2012 Irrevocable Trust.

Footnote F3

The RSUs became fully vested on June 10, 2026, the day prior to the 2026 Annual Meeting of the Stockholders of 908 Devices Inc. The RSUs have no expiration date.

Footnote F4

The RSUs become fully vested on June 11, 2027 or the day prior to the 2027 Annual Meeting of the Stockholders of 908 Devices Inc., whichever occurs first, subject to the reporting person's continued service through the applicable vesting date, provided that, if the reporting person terminates their service for any reason, then a prorated number of RSUs will vest. The RSUs have no expiration date.

Footnote F5

The shares underlying the option become vested and exercisable in substantially equal monthly installments over the 12 months following June 11, 2026, subject to the reporting person's continued service through the applicable vesting date.