MASS (908 Devices Inc. Common Stock)

Insider Trading Activity

Every open-market purchase and sale reported by MASS officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.

Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.

Form 4 Filings
50
most recent
Open-Market Buys
0
code P
Sales
23
code S
Reporting Insiders
21
current holders
MASS — Recent Form 4 Transactions (latest 2026-08-07)
FiledInsiderRole TypeSharesValue
2026-08-07 Christopher D. Brown Director Sell
2026-08-06 AWM Investment Company, Inc. 10%+ Owner Sell
2026-08-03 Brandi C Vann Director M
2026-07-07 Christopher D. Brown Director Sell
2026-07-07 Kevin J. Knopp President and CEO Sell
2026-07-02 Christopher D. Brown Director Sell
2026-06-25 Christopher D. Brown Director Sell
2026-06-25 Kevin J. Knopp President and CEO Sell
2026-06-25 Michele M. Leonhart Director M
2026-06-24 AWM Investment Company, Inc. 10%+ Owner Sell
2026-06-12 Brandi C Vann Director A
2026-06-12 Michele M. Leonhart Director M
2026-06-12 KEITH CRANDELL Director M
2026-06-12 E KEVIN HRUSOVSKY Director M
2026-06-12 Mark Spoto Director M
2026-06-12 FENEL M ELOI Director M
2026-06-12 Anthony Hunt Director M
2026-06-05 Christopher D. Brown Director Sell
2026-06-04 AWM Investment Company, Inc. 10%+ Owner Sell
2026-06-04 Christopher D. Brown Director Sell
2026-05-29 Christopher D. Brown Director Sell
2026-05-29 Joseph H. IV Griffith Chief Financial Officer Sell
2026-05-29 AWM Investment Company, Inc. 10%+ Owner Sell
2026-05-13 AWM Investment Company, Inc. 10%+ Owner Sell
2026-05-11 John Kenneweg SVP, Sales & Product Marketing Sell
2026-05-08 AWM Investment Company, Inc. 10%+ Owner Sell
2026-05-07 Christopher D. Brown Director Sell
2026-05-04 John Kenneweg SVP, Sales & Product Marketing MIXED
2026-04-29 John Kenneweg SVP, Sales & Product Marketing A
2026-04-22 Kolawole A. Otitoju Chief Bus. & Strategy Officer A
2026-04-14 Kevin J. McCallion SVP, Products and Production MIXED
2026-04-10 Kevin J. McCallion SVP, Products and Production MIXED
2026-04-10 Christopher D. Brown Director Sell
2026-03-05 Kevin J. McCallion SVP, Products and Production MIXED
2026-03-04 Kevin J. McCallion SVP, Products and Production Sell
2026-02-03 Mark Spoto Director MIXED
2026-02-03 Christopher D. Brown Director M
2026-02-03 Joseph H. IV Griffith Chief Financial Officer MIXED
2026-02-03 Kevin J. Knopp President and CEO MIXED
2025-10-06 Joseph H. IV Griffith Chief Financial Officer Sell
2025-09-23 Joseph H. IV Griffith Chief Financial Officer Sell
2025-08-18 Brandi C Vann Director A
2025-06-27 Michele M. Leonhart Director M
2025-06-18 Michael S. Turner Chief Legal & Admin Officer Sell
2025-06-13 KEITH CRANDELL Director M
2025-06-13 Marcia Eisenberg Director M
2025-06-13 Jeffrey P. George Director M
2025-06-13 Anthony Hunt Director M
2025-06-13 Mark Spoto Director M
2025-06-13 FENEL M ELOI Director M
MASS — Current Insider Holders
InsiderRole Shares HeldValue
Director 5,764,419
10%+ Owner 5,725,045
10%+ Owner 4,829,773
President and CEO 1,273,826
Director 1,077,091
Director 823,359
Director 495,065
Chief Financial Officer 132,956
Director 92,945
VP, Corporate Development 80,000
SVP, Sales & Product Marketing 57,784
SVP, Products and Production 44,925
Director 44,168
Director 40,897
VP, Corporate Development 28,920
Director 27,054
Director 26,814
Director 25,957
Director 5,192
VP, Product Management & Mktg 2,834
Chief Legal & Admin Officer 1,373
How to read Form 4 activity

Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.

Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.

Full filing history and per-insider positions are on the MASS quote page; the site-wide leaderboard is on the insider transactions hub.