SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* EcoR1 Capital, LLC (Last) (First) (Middle) 357 TEHAMA STREET #3 (Street) SAN FRANCISCO CA 94103 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ANAPTYSBIO, INC [ ANAB ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 04/30/2021
	4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	04/30/2021		P		35,700(2)	A	$23.1601	7,334,624(2)	I	See Note 1(1)
Common Stock	05/03/2021		P		20,800(3)	A	$23.3112	7,355,424(3)	I	See Note 1(1)
Common Stock	05/04/2021		P		165,000(4)	A	$23.247	7,520,424(4)	I	See Note 1(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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* EcoR1 Capital, LLC (Last) (First) (Middle) 357 TEHAMA STREET #3 (Street) SAN FRANCISCO CA 94103 (City) (State) (Zip)

1. Name and Address of Reporting Person* NODELMAN OLEG (Last) (First) (Middle) 357 TEHAMA STREET #3 (Street) SAN FRANCISCO CA 94103 (City) (State) (Zip)

Explanation of Responses:

1. The filing persons (the "Filers") are EcoR1 Capital, LLC ("EcoR1"), Oleg Nodelman and EcoR1 Capital Fund Qualified, L.P. ("Qualified Fund"). EcoR1 is the investment adviser and general partner of private funds, including Qualified Fund (collectively, the "Funds"). Mr. Nodelman is the manager and controlling owner of EcoR1 and a director of the Issuer. EcoR1 is filing this Form 4 for itself and Qualified Fund. The Filers are filing this Form 4 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934, as amended. The Funds hold these securities directly for the benefit of their investors. EcoR1 indirectly beneficially owns them as the investment adviser to the Funds, and Mr. Nodelman indirectly beneficially owns them as the control person of EcoR1. The Filers disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

2. Qualified Fund purchased all of the securities in this transaction. After the transaction, Qualified Fund held 6,188,266 shares of the Issuer's Common Stock.

3. Qualified Fund purchased all of the securities in this transaction. After the transaction, Qualified Fund held 6,209,066 shares of the Issuer's Common Stock.

4. Qualified Fund purchased all of the securities in this transaction. After the transaction, Qualified Fund held 6,374,066 shares of the Issuer's Common Stock.

	Oleg Nodelman, Individually and as Manager of EcoR1 Capital, LLC	05/04/2021
	** Signature of Reporting Person	Date
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