Michele M. Leonhart - 25 Jun 2026 Form 4 Insider Report for 908 Devices Inc. (MASS)

Reporting relationship: Director
Issuer ticker: MASS
Reported as of: 25 Jun 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 25 Jun 2026, 16:15:08 UTC
Prior SEC filing: 12 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Mark S. Levine, Attorney-in-Fact

Key filing fact

Michele M. Leonhart filed Form 4 for 908 Devices Inc. (MASS) on 25 Jun 2026.

Key facts

This page summarizes Michele M. Leonhart's Form 4 filing for 908 Devices Inc. (MASS).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 25 Jun 2026, 16:15.

Change

Previous filing in this sequence was filed on 12 Jun 2026.
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 0002027457 Primary reporting owner

Leonhart Michele M.

Relationship: Director
Address: C/O 908 DEVICES INC., 44 3RD AVENUE, BURLINGTON
Signature: /s/ Mark S. Levine, Attorney-in-Fact
Signature date: 25 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: +6,486
Change %: +32%
Price
Shares after: 27,054
Date: 25 Jun 2026
Ownership: Direct
Footnotes: F1

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: -6,486
Change %: -50%
Price: $0.000000^*
Shares after: 6,485
Date: 25 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 6,486
Exercise price
Footnotes: F1, F2

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 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 RSUs become vested in substantially equal annual installments over the 3 years following June 25, 2024, 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.