Keutzer Timothy 4

4 · Spero Therapeutics, Inc. · Filed Feb 5, 2026

AI-generated summary of this filing

Updated Feb 5, 2026

Spero Therapeutics COO Timothy Keutzer Sells Shares, Receives RSUs & Options

What Happened

Timothy Keutzer, Chief Operating Officer of Spero Therapeutics (SPRO), reported sales totaling 46,586 shares across Feb 2–4, 2026 for proceeds of about $101,174, and received equity awards on Feb 2, 2026: 68,000 restricted stock units (RSUs) and a derivative award covering 137,000 shares (stock option grant).
Sales detail: 18,891 shares sold on 2026-02-02 at $2.20 ($41,560), 24,224 shares sold on 2026-02-03 at $2.14 ($51,839), and 3,471 shares sold on 2026-02-04 at $2.24 ($7,775). The RSUs and option grant were reported at $0.00 acquisition price (standard for awards).

Key Details

Transaction dates & prices:
- 2026-02-02: 18,891 shares sold @ $2.20 (F2)
- 2026-02-03: 24,224 shares sold @ $2.14
- 2026-02-04: 3,471 shares sold @ $2.24
- 2026-02-02: 68,000 RSUs granted (A)
- 2026-02-02: 137,000-share derivative award (A, option)
Shares owned after transaction: Not specified in the provided filing excerpt.
Footnotes of note:
- F1: 68,000 RSUs — each converts to one share; vest in four equal annual installments beginning Feb 2, 2027, subject to continued service.
- F2: The 18,891-share sale was a sell-to-cover to satisfy tax withholding on vesting RSUs (automatic, not a discretionary trade).
- F3: The 137,000-share derivative (option) vests 25% on Feb 2, 2027, then monthly over the next 36 months, subject to continued service.
Filing date: Form filed Feb 5, 2026. (No late-filing flag was provided in the excerpt.)

Context

The reported sale on Feb 2 was an automatic sell-to-cover for tax withholding related to RSU vesting (not an active market-timing decision). The other sales were open-market disposals.
The awards are standard compensation grants (RSUs and options) with multi-year vesting schedules; option grant details indicate future vesting, not immediate exercised-and-sold shares.
For retail investors, award grants are routine executive compensation; sell-to-cover transactions are common and do not necessarily indicate negative insider sentiment.

Form 4

Period: 2026-02-02

Chief Operating Officer

Transactions

Award
Common Stock
[F1]
2026-02-02+68,000→ 807,744 total
Sale
Common Stock
[F2]
2026-02-02$2.20/sh−18,891$41,560→ 788,853 total
Sale
Common Stock
[F2]
2026-02-03$2.14/sh−24,224$51,839→ 764,629 total
Sale
Common Stock
[F2]
2026-02-04$2.24/sh−3,471$7,775→ 761,158 total
Award
Stock Option (Right to Buy)
[F3]
2026-02-02+137,000→ 137,000 total
Exercise: $2.23Exp: 2026-02-02→ Common Stock (137,000 underlying)

Footnotes (3)

[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.
[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.
[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.

Signature

/s/ Maegan Deare, Attorney-in-Fact for Timothy Keutzer|2026-02-04

1 file