908 Devices Inc. (MASS) Insider Trading

Last 12 months

Insiders sold $5.78M and bought nothing on the open market.

90% of the selling was scheduled in advance under 10b5-1 plans. SVP, Sales & Product Marketing John Kenneweg sold $148k on May 8, 24% of their stake, outside a plan. The last open-market buy by an executive or director was in May 2025.

Net open-market

−$5.78M

0 buys · 28 sales

Under a 10b5-1 plan

90%

of the value sold

Insiders who bought / sold

0 / 5

executives and directors

Last open-market buy

May 2025

May 15, 2025

Get an email when MASS's executives or directors buy, or make a large sale outside a plan.

Trades · last 2 years

Date	Insider	Trade	Shares	Price	Value	Of their stake	Filing
Oct 7	Christopher D. Brown Director	Sold10b5-1 plan	30,000	$11.89	$357k	3.6%	Form 4
Oct 6	Joseph H. Griffith IV Chief Financial Officer	Sold10b5-1 plan	5,000	$13.03	$65k	4.1%	Form 4
Sep 29	AWM Investment Company, Inc. Large holder	SoldNo plan	18,000	$11.52	$207k	0.4%	Form 4
Sep 23 – 24	AWM Investment Company, Inc. Large holder	SoldNo plan 2 parts	25,000	$11.36 average	$284k	0.3%	Form 4
Sep 15 – 17	John Kenneweg SVP, Sales & Product Marketing	Sold10b5-1 plan 3 parts	27,656	$10.13 average	$280k	32%	Form 4
Sep 2	Christopher D. Brown Director	Sold10b5-1 plan	30,000	$10.58	$317k	3.7%	Form 4
Aug 25	Joseph H. Griffith IV Chief Financial Officer	Sold10b5-1 plan	11,459	$10.95	$125k	8.6%	Form 4
Aug 20 – 21	AWM Investment Company, Inc. Large holder	SoldNo plan 2 parts	50,000	$10.59 average	$530k	1.0%	Form 4
Aug 13 – 17	Kevin J. Knopp President and CEO	Sold10b5-1 plan 2 parts	27,622	$10.27 average	$284k	2.5%	Form 4
Aug 10 – 12	Kevin J. Knopp President and CEO	Sold10b5-1 plan 4 parts	149,013	$9.90 average	$1.48M	12%	Form 4
Aug 10 – 11	Christopher D. Brown Director	Sold10b5-1 plan 2 parts	17,800	$9.12 average	$162k	2.2%	Form 4
Aug 5	Christopher D. Brown Director	Sold10b5-1 plan	20,000	$8.49	$170k	2.4%	Form 4
Aug 4	AWM Investment Company, Inc. Large holder	SoldNo plan	50,000	$8.36	$418k	1.0%	Form 4
Jul 2	Christopher D. Brown Director	Sold10b5-1 plan	2,200	$9.02	$20k	0.3%	Form 4
Jul 2	Kevin J. Knopp President and CEO	Sold10b5-1 plan	222	$9.07	$2k	<0.1%	Form 4
Jun 30	Christopher D. Brown Director	Sold10b5-1 plan	20,000	$8.84	$177k	2.3%	Form 4
Jun 26	Kevin J. Knopp President and CEO	Sold10b5-1 plan	2,798	$9.09	$25k	0.2%	Form 4
Jun 23 – 25	Kevin J. Knopp President and CEO	Sold10b5-1 plan 3 parts	60,345	$9.12 average	$551k	4.5%	Form 4
Jun 23	Christopher D. Brown Director	Sold10b5-1 plan	9,900	$9.04	$89k	1.1%	Form 4
Jun 22 – 23	AWM Investment Company, Inc. Large holder	SoldNo plan 2 parts	7,718	$8.99 average	$69k	0.2%	Form 4
Jun 4	Christopher D. Brown Director	Sold10b5-1 plan	100	$9.00	$900	<0.1%	Form 4
Jun 2 – 4	AWM Investment Company, Inc. Large holder	SoldNo plan 2 parts	42,282	$8.97 average	$379k	0.9%	Form 4
Jun 3	Christopher D. Brown Director	Sold10b5-1 plan	20,000	$8.73	$175k	2.2%	Form 4
May 28	Christopher D. Brown Director	Sold10b5-1 plan	30,000	$9.00	$270k	3.2%	Form 4
May 27 – 28	AWM Investment Company, Inc. Large holder	SoldNo plan 3 parts	186,942	$8.62 average	$1.61M	3.7%	Form 4
May 28	Joseph H. Griffith IV Chief Financial Officer	Sold10b5-1 plan	6,940	$9.03	$63k	5.0%	Form 4
May 11	AWM Investment Company, Inc. Large holder	SoldNo plan	5,000	$8.25	$41k	<0.1%	Form 4
May 8	John Kenneweg SVP, Sales & Product Marketing	SoldNo plan	18,255	$8.11	$148k	24%	Form 4
May 6 – 8	AWM Investment Company, Inc. Large holder	SoldNo plan 4 parts	78,209	$8.08 average	$632k	1.5%	Form 4
May 6	Christopher D. Brown Director	Sold10b5-1 plan	20,000	$7.23	$145k	2.1%	Form 4
May 1	John Kenneweg SVP, Sales & Product Marketing	SoldNo plan	7,787	$6.83	$53k	9.3%	Form 4
Apr 10	Kevin J. McCallion SVP, Products and Production	Sold10b5-1 plan	2,693	$7.01	$19k	5.7%	Form 4
Apr 8 – 10	Christopher D. Brown Director	Sold10b5-1 plan 3 parts	40,000	$7.06 average	$282k	4.1%	Form 4
Apr 8 – 9	Kevin J. McCallion SVP, Products and Production	Sold10b5-1 plan 2 parts	24,000	$7.05 average	$169k	35%	Form 4
Mar 2	Kevin J. McCallion SVP, Products and Production	Sold10b5-1 plan	7	$7.00	$49	<0.1%	Form 4
Feb 2	Kevin J. Knopp President and CEO	SoldNo plan	34,764	$6.18	$215k	2.5%	Form 4
Feb 2	Joseph H. Griffith IV Chief Financial Officer	SoldNo plan	23,175	$6.18	$143k	14%	Form 4
Oct 2, 2025 – Oct 3, 2025	Joseph H. Griffith IV Chief Financial Officer	Sold10b5-1 plan 2 parts	5,000	$9.05 average	$45k	5.1%	Form 4
Sep 19, 2025	Joseph H. Griffith IV Chief Financial Officer	Sold10b5-1 plan	5,000	$7.07	$35k	4.9%	Form 4
Jun 16, 2025 – Jun 18, 2025	Michael S. Turner Chief Legal & Admin Officer	Sold10b5-1 plan 3 parts	24,603	$7.51 average	$185k	100%	Form 4

Oct 710b5-1 plan
Christopher D. Brown
Director · sold 30,000 at $11.89
$357k
3.6% of stake
Oct 610b5-1 plan
Joseph H. Griffith IV
Chief Financial Officer · sold 5,000 at $13.03
$65k
4.1% of stake
Sep 29No plan
AWM Investment Company, Inc.
Large holder · sold 18,000 at $11.52
$207k
0.4% of stake
Sep 23 – 24No plan
AWM Investment Company, Inc.
Large holder · sold 25,000 at avg $11.36
$284k
0.3% of stake
Sep 15 – 1710b5-1 plan
John Kenneweg
SVP, Sales & Product Marketing · sold 27,656 at avg $10.13
$280k
32% of stake
Sep 210b5-1 plan
Christopher D. Brown
Director · sold 30,000 at $10.58
$317k
3.7% of stake
Aug 2510b5-1 plan
Joseph H. Griffith IV
Chief Financial Officer · sold 11,459 at $10.95
$125k
8.6% of stake
Aug 20 – 21No plan
AWM Investment Company, Inc.
Large holder · sold 50,000 at avg $10.59
$530k
1.0% of stake
Aug 13 – 1710b5-1 plan
Kevin J. Knopp
President and CEO · sold 27,622 at avg $10.27
$284k
2.5% of stake
Aug 10 – 1210b5-1 plan
Kevin J. Knopp
President and CEO · sold 149,013 at avg $9.90
$1.48M
12% of stake
Aug 10 – 1110b5-1 plan
Christopher D. Brown
Director · sold 17,800 at avg $9.12
$162k
2.2% of stake
Aug 510b5-1 plan
Christopher D. Brown
Director · sold 20,000 at $8.49
$170k
2.4% of stake
Aug 4No plan
AWM Investment Company, Inc.
Large holder · sold 50,000 at $8.36
$418k
1.0% of stake
Jul 210b5-1 plan
Christopher D. Brown
Director · sold 2,200 at $9.02
$20k
0.3% of stake
Jul 210b5-1 plan
Kevin J. Knopp
President and CEO · sold 222 at $9.07
$2k
<0.1% of stake
Jun 3010b5-1 plan
Christopher D. Brown
Director · sold 20,000 at $8.84
$177k
2.3% of stake
Jun 2610b5-1 plan
Kevin J. Knopp
President and CEO · sold 2,798 at $9.09
$25k
0.2% of stake
Jun 23 – 2510b5-1 plan
Kevin J. Knopp
President and CEO · sold 60,345 at avg $9.12
$551k
4.5% of stake
Jun 2310b5-1 plan
Christopher D. Brown
Director · sold 9,900 at $9.04
$89k
1.1% of stake
Jun 22 – 23No plan
AWM Investment Company, Inc.
Large holder · sold 7,718 at avg $8.99
$69k
0.2% of stake
Jun 410b5-1 plan
Christopher D. Brown
Director · sold 100 at $9.00
$900
<0.1% of stake
Jun 2 – 4No plan
AWM Investment Company, Inc.
Large holder · sold 42,282 at avg $8.97
$379k
0.9% of stake
Jun 310b5-1 plan
Christopher D. Brown
Director · sold 20,000 at $8.73
$175k
2.2% of stake
May 2810b5-1 plan
Christopher D. Brown
Director · sold 30,000 at $9.00
$270k
3.2% of stake
May 27 – 28No plan
AWM Investment Company, Inc.
Large holder · sold 186,942 at avg $8.62
$1.61M
3.7% of stake
May 2810b5-1 plan
Joseph H. Griffith IV
Chief Financial Officer · sold 6,940 at $9.03
$63k
5.0% of stake
May 11No plan
AWM Investment Company, Inc.
Large holder · sold 5,000 at $8.25
$41k
<0.1% of stake
May 8No plan
John Kenneweg
SVP, Sales & Product Marketing · sold 18,255 at $8.11
$148k
24% of stake
May 6 – 8No plan
AWM Investment Company, Inc.
Large holder · sold 78,209 at avg $8.08
$632k
1.5% of stake
May 610b5-1 plan
Christopher D. Brown
Director · sold 20,000 at $7.23
$145k
2.1% of stake
May 1No plan
John Kenneweg
SVP, Sales & Product Marketing · sold 7,787 at $6.83
$53k
9.3% of stake
Apr 1010b5-1 plan
Kevin J. McCallion
SVP, Products and Production · sold 2,693 at $7.01
$19k
5.7% of stake
Apr 8 – 1010b5-1 plan
Christopher D. Brown
Director · sold 40,000 at avg $7.06
$282k
4.1% of stake
Apr 8 – 910b5-1 plan
Kevin J. McCallion
SVP, Products and Production · sold 24,000 at avg $7.05
$169k
35% of stake
Mar 210b5-1 plan
Kevin J. McCallion
SVP, Products and Production · sold 7 at $7.00
$49
<0.1% of stake
Feb 2No plan
Kevin J. Knopp
President and CEO · sold 34,764 at $6.18
$215k
2.5% of stake
Feb 2No plan
Joseph H. Griffith IV
Chief Financial Officer · sold 23,175 at $6.18
$143k
14% of stake
Oct 2, 2025 – Oct 3, 202510b5-1 plan
Joseph H. Griffith IV
Chief Financial Officer · sold 5,000 at avg $9.05
$45k
5.1% of stake
Sep 19, 202510b5-1 plan
Joseph H. Griffith IV
Chief Financial Officer · sold 5,000 at $7.07
$35k
4.9% of stake
Jun 16, 2025 – Jun 18, 202510b5-1 plan
Michael S. Turner
Chief Legal & Admin Officer · sold 24,603 at avg $7.51
$185k
100% of stake

How to read this. Insiders sell for many reasons: taxes, diversifying, a house. Open-market buys are rarer and say more. A 10b5-1 plan is a trading schedule set up months in advance, so those sales were not timed on news. Large holders (funds and 10% owners) are listed under Everything but not counted as insiders. If you own or watch MASS, we send a push when an executive buys or makes a large sale outside a plan.

Source: SEC Form 4 filings, filed within two business days of each trade and checked for new ones every hour.

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Data sourced from SEC EDGAR filings and third-party price providers. Scores, valuations, and metrics are algorithmic estimates. This is not investment advice. See our Terms and Methodology.

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