Form 4: Spero Therapeutics COO Reports Equity Transactions

Spero Therapeutics' Chief Operating Officer, Timothy Keutzer, reported the acquisition of restricted stock units and stock options, alongside 'sell to cover' transactions for tax obligations.

Summary

• Timothy Keutzer, Chief Operating Officer of Spero Therapeutics, Inc. (SPRO), reported changes in his beneficial ownership.
• Acquired 68,000 shares of Common Stock in the form of Restricted Stock Units (RSUs) at a price of $0.00 per share.
• Acquired 137,000 Stock Options with an exercise price of $2.23 per share.
• Disposed of a total of 46,586 shares of Common Stock through "sell to cover" transactions to satisfy tax withholding obligations.
• These sales occurred on February 2, 2026 (18,891 shares at $2.20), February 3, 2026 (24,224 shares at $2.14), and February 4, 2026 (3,471 shares at $2.24).
• Following these transactions, Keutzer beneficially owns 761,158 shares of Common Stock directly and 137,000 derivative securities (stock options).

Sentiment

Score: 6

Explanation: StockSavvy.ai views this as slightly positive due to the significant equity grants to a key executive, indicating continued commitment and alignment of interests, despite the routine tax-related share sales.

Positives

• Grant of 68,000 Restricted Stock Units (RSUs) to the Chief Operating Officer, aligning management's interests with shareholders.
• Grant of 137,000 Stock Options with an exercise price of $2.23, providing future upside potential for the COO.

Negatives

• Disposal of 46,586 shares of Common Stock through "sell to cover" transactions, which, while non-discretionary for tax purposes, reduces the COO's direct shareholding.

Future Outlook

The Restricted Stock Units (RSUs) will vest in four equal annual installments beginning on February 2, 2027, contingent on continued service. The Stock Options will vest 25% on February 2, 2027, with the remaining portion vesting in 36 equal monthly installments thereafter, also subject to continued service.

Management Comments

• The sales represent 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.

Industry Context

StockSavvy.ai notes that equity grants, such as Restricted Stock Units and stock options, are standard components of executive compensation packages in the biotechnology and pharmaceutical industries. These grants are designed to align the interests of executives with long-term shareholder value creation, while "sell to cover" transactions for tax obligations are a routine and non-discretionary aspect of such compensation.

Stakeholder Impact

• Shareholders: Minor potential dilution from new equity grants, but also increased alignment of executive incentives with long-term company performance. The "sell to cover" transactions have a negligible impact on overall share count.

Next Steps

• Vesting of Restricted Stock Units (RSUs) in four equal annual installments beginning February 2, 2027.
• Vesting of Stock Options: 25% on February 2, 2027, with the remainder vesting in 36 equal monthly installments thereafter.

Key Dates

Keywords

Spero Therapeutics, SPRO, Timothy Keutzer, Chief Operating Officer, Insider Trading, Form 4, Restricted Stock Units, Stock Options, Equity Compensation, Beneficial Ownership