Form 4 for MASS 908 Devices Inc.
Accepted 2026-02-03 00:00:00 ET · period of report 2026-02-01 · accession 0001836988-26-000002 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| DM | 2026-02-03 | 2026-02-01 | MASS | Brown Christopher D. | Dir | M - OptEx | — | +23.4K | 967.1K | +2% | — |
| DM | 2026-02-03 | 2026-02-01 | MASS | Brown Christopher D. | Dir | M - OptEx | $0.00 | -23.4K | 0 | -100% | $0 |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2026-02-01 | M | A | 10,992 | — | 985,559 | D | — | — | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. |
| 2 | Common | Common Stock | 2026-02-01 | M | A | 7,418 | — | 974,567 | D | — | — | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. |
| 3 | Common | Common Stock | 2026-02-01 | M | A | 5,027 | — | 967,149 | D | — | — | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. |
| 4 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 10,992 | $0.00 | 21,982 | D | — · — to — | 10,992 Common Stock | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. (F4) These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2024, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date. |
| 5 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 7,418 | $0.00 | 7,418 | D | — · — to — | 7,418 Common Stock | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. (F3) These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2023, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date. |
| 6 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 5,027 | $0.00 | 0 | D | — · — to — | 5,027 Common Stock | (F1) Each Restricted Stock Unit ("RSU") represents a contingent right to receive, at settlement, one share of Common Stock. This transaction represents the settlement of RSUs in shares of Common Stock on their scheduled vesting date. (F2) These RSUs vest in four substantially equal annual installments at the four anniversary dates following February 1, 2022, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date. |