InsiderTrades

Form 4 for SPRO Spero Therapeutics, Inc.

Accepted 2026-02-05 00:00:00 ET · period of report 2026-02-02 · accession 0001193125-26-038441 · 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 2026-02-05 2026-02-02+ SPRO Keutzer Timothy COO S - Sale $2.17 -46.6K 788.9K -6% -$101.2K
D 2026-02-05 2026-02-02 SPRO Keutzer Timothy COO A - Grant $0.00 +68.0K 807.7K +9% $0
D 2026-02-05 2026-02-02 SPRO Keutzer Timothy COO A - Grant $0.00 +137.0K 137.0K New $0

Purchase Sale Sale after option exercise All abbreviations

Every reported transaction

#TableSecurityDateCodeA/DSharesPriceOwned afterOwnExercise / expiryUnderlyingFootnotes
1 Common Common Stock 2026-02-04 S D 3,471 $2.24 761,158 D — — (F2) Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.
2 Common Common Stock 2026-02-03 S D 24,224 $2.14 764,629 D — — (F2) Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.
3 Common Common Stock 2026-02-02 S D 18,891 $2.20 788,853 D — — (F2) Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.
4 Common Common Stock 2026-02-02 A A 68,000 $0.00 807,744 D — — (F1) Consists of restricted stock units ("RSUs") granted to Reporting Person under Issuer's 2017 Stock Incentive Plan. Each RSU represents the right to receive one share of common stock upon vesting. The RSUs vest in four equal annual installments beginning on February 2, 2027, subject to the Reporting Person's continued service through the applicable vesting date.
5 Derivative Stock Option (Right to Buy) 2026-02-02 A A 137,000 $0.00 137,000 D $2.23 · — to 2026-02-02 137,000 Common Stock (F3) The shares underlying this option vest as to 25% on February 2, 2027, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date.