SEC FORM 3 SEC Form 3
FORM 3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
 
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1. Name and Address of Reporting Person*
Aquilo Capital Management, LLC

(Last) (First) (Middle)
ONE LETTERMAN DRIVE
SUITE D4900, BUILDING D

(Street)
SAN FRANCISCO CA 94129

(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
09/11/2020
3. Issuer Name and Ticker or Trading Symbol
Spero Therapeutics, Inc. [ SPRO ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director X 10% Owner
Officer (give title below) Other (specify below)
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
Form filed by One Reporting Person
X Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, $0.001 Par Value(1) 4,497,142 I See Footnotes
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
1. Name and Address of Reporting Person*
Aquilo Capital Management, LLC

(Last) (First) (Middle)
ONE LETTERMAN DRIVE
SUITE D4900, BUILDING D

(Street)
SAN FRANCISCO CA 94129

(City) (State) (Zip)
1. Name and Address of Reporting Person*
Aquilo Capital, L.P.

(Last) (First) (Middle)
ONE LETTERMAN DRIVE, SUITE D4900
BUILDING D, THE PRESIDIO

(Street)
SAN FRANCISCO CA 94129

(City) (State) (Zip)
Explanation of Responses:
1. 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 that holds 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 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.
Aquilo Capital Management, LLC By: Managing Member /s/ Marc Schneidman 09/22/2020
Aquilo Capital, L.P., By: Aquilo Capital Management, LLC, its General Partner By: Marc Schneidman, its Managing Member /s/ Marc Schneidman 09/22/2020
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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