Spero Therapeutics, Inc. — Director's Dealing 2020

Nov 5, 2020

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Spero Therapeutics, Inc. (SPRO)
CIK: 0001701108
Period of Report: 2020-11-03

Reporting Person: Mahadevia Ankit (Director, CEO and President)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2020-11-03	Common Stock	M	2137	$5.90	Acquired	67954	Direct
2020-11-03	Common Stock	S	2137	$14.2675	Disposed	65817	Direct
2020-11-04	Common Stock	M	7370	$5.90	Acquired	73187	Direct
2020-11-04	Common Stock	S	7370	$14.4281	Disposed	65817	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2020-11-03	Stock Option (Right to Buy)	$5.90	M	2137	Disposed	2027-07-05	Common Stock (2137)	Direct
2020-11-04	Stock Option (Right to Buy)	$5.90	M	7370	Disposed	2027-07-05	Common Stock (7370)	Direct

Footnotes

F1: All transactions reported on this Form 4 were made pursuant to a previously adopted Rule 10b5-1 trading plan. Specifically, the transactions reported herein relate to option exercises and related sales (totaling 9,507
shares).

F2: Amount includes shares of common stock held by the Mahadevia-Mehta Family Trust, of which the Reporting Person is a trustee.

F3: The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $14.25 to $14.35 per share. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

F4: The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $14.25 to $14.63 per share. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

F5: All of the option exercises reported herein were made with respect to options granted pursuant to the Company's 2017 Equity Incentive Plan on July 6, 2017 with vesting schedules generally consisting of 25% cliff vesting on specified dates and with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date.