InsiderTrades

Form 4 for MASS 908 Devices Inc.

Accepted 2026-04-14 16:00:05 ET · period of report 2026-04-10 · accession 0002115341-26-000012 · 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
DT 2026-04-14 16:00 2026-04-10 MASS McCallion Kevin J. SVP, Products, Production M - OptEx $1.05 +2,693 47.6K +6% +$2,828
DT 2026-04-14 16:00 2026-04-10 MASS McCallion Kevin J. SVP, Products, Production S - Sale+OE $7.01 -2,693 44.9K -6% -$18.9K
DT 2026-04-14 16:00 2026-04-10 MASS McCallion Kevin J. SVP, Products, Production M - OptEx $0.00 -2,693 0 -100% $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-04-10 M A 2,693 $1.05 47,618 D — — (F1) This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 9, 2025.
2 Common Common Stock 2026-04-10 S D 2,693 $7.01 44,925 D — — (F1) This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 9, 2025. (F2) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $7.00 to $7.03 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the 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 range set forth in this footnote.
3 Derivative Stock Option (right to buy) 2026-04-10 M D 2,693 $0.00 0 D $1.05 · — to 2030-08-27 2,693 Common Stock (F1) This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 9, 2025. (F3) The shares underlying the option are fully vested and immediately exercisable. (F4) Due to a scrivener's error on the Form 3, the number of stock options beneficially owned by the Reporting Person pursuant to this grant was understated by 7. Following this transaction, the entire option grant has been exercised.