Spero Therapeutics, Inc. — Director's Dealing 2021

Feb 4, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Spero Therapeutics, Inc. (SPRO)
CIK: 0001701108
Period of Report: 2021-02-01

Reporting Person: Aquilo Capital Management, LLC (10% Owner)
Reporting Person: Aquilo Capital, L.P. (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-02-01	Common Stock, $0.001 Par Value	S	13661	$19.2417	Disposed	3918548	Indirect
2021-02-02	Common Stock, $0.001 Par Value	S	22841	$18.9909	Disposed	3895707	Indirect
2021-02-03	Common Stock, $0.001 Par Value	S	29354	$18.9787	Disposed	3866353	Indirect
2021-02-04	Common Stock, $0.001 Par Value	S	34144	$18.9859	Disposed	3832209	Indirect

Footnotes

F1: The reporting persons are Aquilo Capital, L.P. (the "Fund"), Aquilo Capital Management, LLC ("Aquilo") and Marc R. Schneidman. Aquilo is the general partner and investment adviser of the Fund and other funds managed by Aquilo that hold securities directly for the benefit of their investors. Aquilo may be deemed to beneficially own such securities indirectly as the investment adviser and general partner of the Fund and affiliated funds, and Mr. Schneidman may be deemed to beneficially own them indirectly as the control person of Aquilo. Each of Aquilo, the Fund and Mr. Schneidman disclaims beneficial ownership of such securities except to the extent of his or its pecuniary interest therein.