Sec Form 4 Filing - Hayden Michael R @ 89bio, Inc. - 2021-02-23

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Hayden Michael R 2. Issuer Name and Ticker or Trading Symbol 89bio, Inc. [ ETNB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O 89BIO, INC., 142 SANSOME STREET, 2ND FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/23/2021 (Street) SAN FRANCISCO, CA94104 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/23/2021 M 60,820 A $ 1.93 60,820 D Common Stock 02/23/2021 M 6,447 A $ 1.93 67,267 D Common Stock 02/23/2021 M 13,637 A $ 3.11 80,904 D Common Stock 77,728 I See footnote ( 1 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Stock Option (Right to Buy) $ 1.93 02/23/2021 M 60,820 ( 2 ) 11/09/2028 Common Stock 60,820 $ 0 27,647 D Stock Option (Right to Buy) $ 1.93 02/23/2021 M 6,447 ( 3 ) 01/30/2029 Common Stock 6,447 $ 0 2,933 D Stock Option (Right to Buy) $ 3.11 02/23/2021 M 13,637 ( 4 ) 07/30/2029 Common Stock 13,637 $ 0 22,730 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Hayden Michael R C/O 89BIO, INC. 142 SANSOME STREET, 2ND FLOOR SAN FRANCISCO, CA94104 X Signatures /s/ Ryan A. Murr, as attorney-in-fact for Michael R. Hayden 02/25/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These shares are held directly by Genworks 2 Consulting Inc., over which the Reporting Person's wife has sole voting and investment power. ( 2 )This option represents a right to purchase a total of 88,467 shares of the Issuer's common stock, one quarter of which vested on April 16, 2019, with the remaining three quarters vesting in equal quarterly installments over the following three years. ( 3 )This option represents a right to purchase a total of 9,380 shares of the Issuer's common stock, one quarter of which vested on April 16, 2019, with the remaining three quarters vesting in equal quarterly installments over the following three years. ( 4 )This option represents a right to purchase a total of 36,367 shares of the Issuer's common stock, one quarter of which vested on July 23, 2020, with the remaining three quarters vesting in equal quarterly installments over the following three years.

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 4(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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