908 Devices Inc. Insider Trading Activity
Every SEC Form 4 insider transaction reported for 908 Devices Inc. (MASS), sourced directly from SEC EDGAR and updated as new filings are accepted.
By Trabud · Insider-trading data from SEC EDGAR
Latest filing:
Compiled automatically from SEC EDGAR Form 4 filings and refreshed daily. Figures count purchases (code P) and sales (code S) only — not grants, option exercises, or gifts. How this page is built. Not investment advice.
Quick Answer
Are MASS insiders buying or selling?
In the last 12 months, 908 Devices Inc. insiders reported 0 open-market purchases ($0) and 37 sales ($10.0M) — net selling of $10.0M. Since December 2020, Trabud has recorded 132 Form 4 filings for MASS: 17 buys ($16.0M) and 115 sells ($38.7M).
Source: SEC EDGAR Form 4
What stands out
- No 908 Devices Inc. insider made an open-market purchase in the last 12 months; the 37 reported open-market sales totaled $10.0M.
Key Statistics (December 2020 – Oct 9, 2026)
Total Form 4 filings
132
SEC EDGAR
Insider filers
15
Insider buys (17)
$16.0M
Insider sells (115)
$38.7M
Insider sentiment
Net sellingNet insider flow of $22.7M in net selling since December 2020, and $10.0M in net selling over the last 12 months.
Recent MASS insider transactions
| Date | Insider | Role | Type | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Oct 9, 2026 | Christopher D. Brown | Director | Sale | 30.0K | $11.89 | $356.7K | SEC ↗ |
| Oct 8, 2026 | Joseph H. Griffith IV | Chief Financial Officer | Sale | 5.0K | $13.03 | $65.2K | SEC ↗ |
| Oct 1, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 18.0K | $11.52 | $207.3K | SEC ↗ |
| Sep 25, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 25.0K | $11.36 | $283.9K | SEC ↗ |
| Sep 17, 2026 | John Kenneweg | SVP, Sales & Product Marketing | Sale | 27.7K | $10.13 | $280.1K | SEC ↗ |
| Sep 4, 2026 | Christopher D. Brown | Director | Sale | 30.0K | $10.58 | $317.4K | SEC ↗ |
| Aug 27, 2026 | Joseph H. Griffith IV | Chief Financial Officer | Sale | 11.5K | $10.95 | $125.5K | SEC ↗ |
| Aug 24, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 50.0K | $10.60 | $529.8K | SEC ↗ |
| Aug 17, 2026 | Kevin J. Knopp | President and CEO | Sale | 27.6K | $10.27 | $283.7K | SEC ↗ |
| Aug 12, 2026 | Christopher D. Brown | Director | Sale | 17.8K | $9.12 | $162.4K | SEC ↗ |
| Aug 12, 2026 | Kevin J. Knopp | President and CEO | Sale | 149.0K | $9.90 | $1.5M | SEC ↗ |
| Aug 7, 2026 | Christopher D. Brown | Director | Sale | 20.0K | $8.49 | $169.8K | SEC ↗ |
| Aug 6, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 50.0K | $8.36 | $417.8K | SEC ↗ |
| Jul 7, 2026 | Kevin J. Knopp | President and CEO | Sale | 222 | $9.07 | $2.0K | SEC ↗ |
| Jul 7, 2026 | Christopher D. Brown | Director | Sale | 2.2K | $9.02 | $19.8K | SEC ↗ |
| Jul 2, 2026 | Christopher D. Brown | Director | Sale | 20.0K | $8.84 | $176.8K | SEC ↗ |
| Jun 30, 2026 | Kevin J. Knopp | President and CEO | Sale | 2.8K | $9.09 | $25.4K | SEC ↗ |
| Jun 25, 2026 | Christopher D. Brown | Director | Sale | 9.9K | $9.04 | $89.5K | SEC ↗ |
| Jun 25, 2026 | Kevin J. Knopp | President and CEO | Sale | 60.3K | $9.12 | $550.6K | SEC ↗ |
| Jun 24, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 7.7K | $9.00 | $69.4K | SEC ↗ |
| Jun 5, 2026 | Christopher D. Brown | Director | Sale | 100 | $9.00 | $900 | SEC ↗ |
| Jun 4, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 42.3K | $8.97 | $379.2K | SEC ↗ |
| Jun 4, 2026 | Christopher D. Brown | Director | Sale | 20.0K | $8.73 | $174.6K | SEC ↗ |
| May 29, 2026 | AWM Investment Company, Inc. | 10% Owner | Sale | 186.9K | $8.62 | $1.6M | SEC ↗ |
| May 29, 2026 | Christopher D. Brown | Director | Sale | 30.0K | $9.00 | $270.0K | SEC ↗ |
Showing the 25 most recent of 132 Form 4 filings for 908 Devices Inc..
Most active MASS insiders
- Kevin J. Knopp31 filings
- Christopher D. Brown28 filings
- Joseph H. Griffith IV19 filings
- John Kenneweg12 filings
- Michael S. Turner10 filings
Ask anything about MASS insider activity
Use Trabud's AI agent to query 908 Devices Inc.'s Form 4 history in plain English — "Show me MASS CEO purchases this year" or compare it against any other ticker.
Open the AI agentMASS insider trading FAQ
Are 908 Devices Inc. insiders buying or selling?
In the last 12 months, 908 Devices Inc. insiders reported 0 open-market purchases ($0) and 37 sales ($10.0M) — net selling of $10.0M. Since December 2020, Trabud has recorded 132 Form 4 filings for MASS: 17 buys ($16.0M) and 115 sells ($38.7M). Over the full record that is net selling of $22.7M.
How many insiders trade MASS stock?
15 distinct insider filers — officers, directors, 10%+ owners, and investment groups filing jointly — have reported Form 4 transactions for 908 Devices Inc.. The most recent filing was accepted on Oct 9, 2026.
Where does Trabud get MASS insider trading data?
All MASS insider trading data comes directly from official SEC EDGAR Form 4 filings, which corporate insiders must submit within two business days of a transaction under Section 16(a) of the Securities Exchange Act of 1934.