Ankit Mahadevia - 01 Feb 2022 Form 4 Insider Report for Spero Therapeutics, Inc. (SPRO)

Role: CEO and President, Director
Signature: /s/ Tamara Joseph, Attorney-in-Fact for Ankit Mahadevia
Issuer symbol: SPRO
Transactions as of: 01 Feb 2022
Net transactions value: $0
Form type: 4
Filing time: 03 Feb 2022, 15:18:13 UTC
Previous filing: 29 Dec 2021
Next filing: 03 Feb 2023
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	SPRO	Common Stock	Award	$0	+134,168	+93%	$0.000000	278,204	01 Feb 2022	Direct	F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	SPRO	Stock Option (Right to Buy)	Award	$0	+187,730		$0.000000	187,730	01 Feb 2022	Common Stock	187,730	$11.18	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Consists of restricted stock units ("RSUs"). 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 1, 2023, subject to the Reporting Person's continued service through the applicable vesting date.
F2	Amount includes 65,817 shares of common stock held by the Mahadevia-Mehta Family Trust, of which the Reporting Person is a trustee. Amount also includes 212,387 RSUs held by the Reporting Person.
F3	The shares underlying this option vest as to 25% on February 1, 2023, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date.