Updated Jul 16, 2026 · Last SEC filing 2026-07-07
908 Devices Inc. (MASS) has filed 28 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-07-07. 3 Form 8-K material event filings were reported by MASS in the last 90 days. 4 Form 144 notices of proposed sale were filed for MASS stock. InsiderAlpha tracks every MASS SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SIC classification | Measuring & Controlling Devices, NEC (SIC 3829) |
|---|---|
| SEC CIK | 0001555279 |
| Form 4 filings (90d) | 28 |
|---|---|
| Form 8-K filings (90d) | 3 |
| Form 144 notices (90d) | 4 |
| Latest Form 4 filing | 2026-07-07 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Knopp Kevin J. | President and CEO | S — Open-market sale | 222 | $9.07 | $2K | SEC | |
| Brown Christopher D. | Insider | S — Open-market sale | 2.2K | $9.02 | $20K | SEC | |
| Brown Christopher D. | Insider | S — Open-market sale | 20.0K | $8.84 | $177K | SEC | |
| Knopp Kevin J. | President and CEO | S — Open-market sale | 2.8K | $9.09 | $25K | SEC | |
| Leonhart Michele M. | Insider | M — Option exercise | 6.5K | — | — | SEC | |
| Knopp Kevin J. | President and CEO | S — Open-market sale | 16.4K | $9.10 | $149K | SEC | |
| Knopp Kevin J. | President and CEO | S — Open-market sale | 40.5K | $9.14 | $370K | SEC | |
| Brown Christopher D. | Insider | S — Open-market sale | 9.9K | $9.04 | $89K | SEC | |
| AWM Investment Company, Inc. | 10% Owner | S — Open-market sale | 3.0K | $9.00 | $27K | SEC | |
| Knopp Kevin J. | President and CEO | S — Open-market sale | 3.4K | $9.06 | $31K | SEC | |
| AWM Investment Company, Inc. | 10% Owner | S — Open-market sale | 4.7K | $8.99 | $42K | SEC | |
| CRANDELL KEITH | Insider | M — Option exercise | 14.1K | — | — | SEC | |
| HRUSOVSKY E KEVIN | Insider | M — Option exercise | 14.1K | — | — | SEC | |
| Hunt Anthony | Insider | M — Option exercise | 14.1K | — | — | SEC | |
| Leonhart Michele M. | Insider | M — Option exercise | 14.1K | — | — | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for 908 Devices Inc. (MASS). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| AWM Investment Company, Inc. | 12 | $2.73M |
| Brown Christopher D. | 7 | $876K |
| Leonhart Michele M. | 6 | — |
| Kenneweg John | 5 | $201K |
| Knopp Kevin J. | 5 | $578K |
Form 144 must be filed before insiders sell restricted or control stock above SEC thresholds. A cluster of Form 144 notices often precedes a wave of insider distribution.
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in MASS insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
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