Joseph H. Griffith IV is CFO at 908 Devices Inc. (MASS). They have made 12 open-market trades across 1 company since 2021, most recently 2026-08-25.
CIK 0001431531
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 12 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| MASS | 121,497 | $1.4M |
| CALP | 33,287 | — |
| Total | $1.4M |
Shares reported on the most recent Form 4, priced at the 2026-08-27 close. 1 holding could not be priced and is excluded from the total.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| MASS | SELL · 10b5-1 | 2026-08-25 | 2026-08-27 | $10.95 | $125K | -12.4% | +5.2% | — |
| MASS | SELL · 10b5-1 | 2026-05-28 | 2026-05-29 | $9.03 | $63K | -2.0% | +7.8% | +35.4% |
| MASS | SELL | 2026-02-02 | 2026-02-03 | $6.18 | $143K | +1.2% | +5.3% | +2.0% |
| MASS | SELL · 10b5-1 | 2025-10-02 | 2025-10-06 | $9.05 | $45K | -1.1% | -7.7% | -37.6% |
| MASS | SELL · 10b5-1 | 2025-09-19 | 2025-09-23 | $7.07 | $35K | +19.5% | +10.7% | -21.9% |
| MASS | SELL · 10b5-1 | 2025-06-04 | 2025-06-06 | $7.08 | $49K | +11.8% | -10.1% | -22.9% |
| MASS | SELL | 2025-02-03 | 2025-02-04 | $2.34 | $24K | +18.3% | +28.1% | +129.8% |
| MASS | SELL | 2024-02-01 | 2024-02-02 | $7.07 | $178K | +6.2% | +3.6% | -18.8% |
| MASS | SELL | 2023-12-28 | 2024-01-02 | $12.08 | $72K | -19.1% | -24.8% | -28.1% |
| MASS | SELL | 2023-12-19 | 2023-12-21 | $9.08 | $101K | -4.6% | -10.3% | -24.9% |
| MASS | SELL · 10b5-1 | 2023-02-01 | 2023-02-03 | $9.72 | $50K | +1.1% | -11.9% | -30.9% |
| MASS | SELL | 2022-08-03 | 2022-08-05 | $24.39 | $636K | -30.3% | -27.5% | -42.5% |
| MASS | SELL | 2022-06-24 | 2022-06-27 | $19.12 | $695K | +6.8% | +8.8% | -21.1% |
| MASS | SELL | 2022-06-17 | 2022-06-22 | $15.06 | $135K | +36.8% | +32.6% | +3.1% |
| MASS | SELL · 10b5-1 | 2022-06-15 | 2022-06-17 | $15.02 | $15K | +42.5% | +21.5% | +16.3% |
| MASS | SELL | 2022-06-13 | 2022-06-15 | $13.54 | $361K | +41.6% | +28.8% | +30.2% |
| MASS | SELL | 2021-11-05 | 2021-11-05 | $39.08 | $109K | -19.2% | -35.1% | -59.6% |
| MASS | SELL | 2021-09-08 | 2021-09-10 | $37.61 | $3.8M | +1.2% | -12.2% | -28.2% |
| MASS | SELL | 2021-06-16 | 2021-06-21 | $39.32 | $1.4M | -4.9% | -13.6% | -9.5% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.