Form 4 for MASS 908 Devices Inc.
Accepted 2026-02-03 00:00:00 ET · period of report 2026-02-01 · accession 0001836523-26-000002 · 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 | Knopp Kevin J. | Pres, CEO, Dir | M - OptEx | — | +108.0K | 734.0K | +17% | — |
| D | 2026-02-03 | 2026-02-02 | MASS | Knopp Kevin J. | Pres, CEO, Dir | S - Sale+OE | $6.18 | -34.8K | 796.0K | -4% | -$214.8K |
| DM | 2026-02-03 | 2026-02-02 | MASS | Knopp Kevin J. | Pres, CEO, Dir | A - Grant | $0.00 | +296.0K | 206.0K | New | $0 |
| DM | 2026-02-03 | 2026-02-01 | MASS | Knopp Kevin J. | Pres, CEO, Dir | M - OptEx | $0.00 | -108.0K | 34.0K | -76% | $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 | 66,288 | — | 830,732 | 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 | 2026-02-02 | S | D | 34,764 | $6.18 | 795,968 | D | — | — | (F3) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.105 to $6.32, inclusive. The reporting person undertakes to provide to Issuer, any security holder of Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. |
| 3 | Common | Common Stock | 2026-02-01 | M | A | 17,007 | — | 764,444 | 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 | Common | Common Stock | 2026-02-01 | M | A | 13,449 | — | 747,437 | 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. |
| 5 | Common | Common Stock | 2026-02-01 | M | A | 11,255 | — | 733,988 | 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. |
| 6 | Derivative | Stock Option (option to buy) | 2026-02-02 | A | A | 90,043 | $0.00 | 90,043 | D | $6.19 · — to 2036-02-01 | 90,043 Common Stock | (F10) One-third of the shares underlying the option become vested and exercisable on February 1, 2027, and the remaining two-thirds of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 24 months following February 1, 2027, subject to the reporting person's continued service through the applicable vesting date. |
| 7 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 66,288 | $0.00 | 132,576 | D | — · — to — | 66,288 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. (F8) The RSUs shall vest one-third on February 1, 2026, with the remaining two-thirds vesting in two substantially equal annual installments at the two anniversary dates following February 1, 2026, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date. |
| 8 | Derivative | Restricted Stock Units | 2026-02-02 | A | A | 205,978 | $0.00 | 205,978 | D | — · — to — | 205,978 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. (F9) The RSUs shall vest one-third on February 1, 2027, with the remaining two-thirds vesting in two substantially equal annual installments at the two anniversary dates following February 1, 2027, subject to the reporting person's continued service through the applicable vesting date. The RSUs have no expiration date. |
| 9 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 11,255 | $0.00 | 0 | D | — · — to — | 11,255 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. (F5) 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. |
| 10 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 13,449 | $0.00 | 13,448 | D | — · — to — | 13,449 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. (F6) 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. |
| 11 | Derivative | Restricted Stock Units | 2026-02-01 | M | D | 17,007 | $0.00 | 34,014 | D | — · — to — | 17,007 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. (F7) 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. |