🕵️ 908 Devices Inc. ($MASS)
SEC insider & ownership activity, last 12 months · CIK 1555279 · every row links its SEC filing
Over the last 12 months insiders sold $8.8M with no open-market buying against it. AWM Investment Company, Inc. sold $3.7M (May–Aug). 1 planned sale is pending, the largest $269K (John Kenneweg). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
0 buyers, $0 (0 lots) · 6 sellers, $8.8M (53 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| AWM Investment Company, Inc. | 0 | – | 15 | $3.7M | Aug 21, 2026 |
| Kevin J. Knopp | 0 | – | 12 | $2.6M | Aug 17, 2026 |
| Christopher D. Brown | 0 | – | 14 | $1.8M | Sep 2, 2026 |
| Joseph Griffith | 0 | – | 6 | $412K | Aug 25, 2026 |
| John Wesley Kenneweg | 0 | – | 2 | $201K | May 8, 2026 |
| Kevin McCallion | 0 | – | 4 | $188K | Apr 10, 2026 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Mathew P. Arens | 17.1% | 13G | Feb 17, 2026 | filing ↗ | |
| First Light Asset Management, LLC | 16.5% | 13G | Feb 17, 2026 | filing ↗ | |
| Keith Crandell | 14.1% | 13G | Aug 14, 2026 | filing ↗ | |
| ARCH Venture Fund VII, L.P. | 13.9% | 13G | Aug 14, 2026 | filing ↗ | |
| ARCH Venture Partners VII, L.P. | 13.9% | 13G | Aug 14, 2026 | filing ↗ | |
| ARCH Venture Partners VII, LLC | 13.9% | 13G | Aug 14, 2026 | filing ↗ | |
| Clinton Bybee | 13.9% | 13G | Aug 14, 2026 | filing ↗ | |
| Robert Nelsen | 13.9% | 13G | Aug 14, 2026 | filing ↗ | |
| AWM Investment Company, Inc. | 11.8% | 13G | Aug 14, 2026 | filing ↗ | |
| ARK Investment Management LLC | 8.0% | 13G | Feb 14, 2025 | filing ↗ | |
| ARK Investment Management LLC | 5.3% | 13G | Aug 14, 2026 | filing ↗ | |
| Catherine D. Wood | 5.3% | 13G | Aug 14, 2026 | filing ↗ | |
| BlackRock, Inc. | 5.1% | 13G | Jul 27, 2026 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| John Kenneweg | $269K | Sep 15, 2026 | filing ↗ |
| Joseph Griffith | $125K | Aug 25, 2026 | filing ↗ |
| Kevin Knopp | $205K | Aug 17, 2026 | filing ↗ |
| Kevin Knopp | $1.3M | Aug 11, 2026 | filing ↗ |
| Christopher Brown | $888K | Aug 10, 2026 | filing ↗ |
| Kevin Knopp | $724K | Jun 23, 2026 | filing ↗ |
| Christopher Brown | $620K | Jun 3, 2026 | filing ↗ |
| Joseph Griffith | $57K | May 28, 2026 | filing ↗ |
| John Wesley Kenneweg | $148K | May 8, 2026 | filing ↗ |
| Kevin McCallion | $183K | Apr 8, 2026 | filing ↗ |
| Christopher Brown | $676K | Apr 8, 2026 | filing ↗ |
| Joseph H. Griffith IV | $45K | Oct 2, 2025 | filing ↗ |
| Joseph H. Griffith IV | $34K | Sep 19, 2025 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Earnings (2.02) | Aug 11, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 11, 2026 | filing ↗ |
| Other events (8.01) | Jul 8, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 11, 2026 | filing ↗ |
| Material agreement (1.01) | May 4, 2026 | filing ↗ |
| Acquisition or disposition (2.01) | May 4, 2026 | filing ↗ |
| Earnings (2.02) | May 4, 2026 | filing ↗ |
| Unregistered equity sale (3.02) | May 4, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | May 4, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 4, 2026 | filing ↗ |
| Earnings (2.02) | Mar 3, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 3, 2026 | filing ↗ |
| Earnings (2.02) | Jan 20, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 20, 2026 | filing ↗ |
| Earnings (2.02) | Nov 10, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 10, 2025 | filing ↗ |