Day One Biopharmaceuticals (DAWN) Form 4 Day One Biopharmaceuticals / Charles N York II ownership change

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

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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^*

York Charles N II

(Last) (First) (Middle)

1800 SIERRA POINT PARKWAY, SUITE 200

(Street)

BRISBANE CA 94005

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Day One Biopharmaceuticals, Inc. [ DAWN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
COO, CFO AND SECRETARY

3. Date of Earliest Transaction (Month/Day/Year)
02/15/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	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	02/15/2025		M		1,375	A	(1)	241,508	D
Common Stock	02/15/2025		M		2,250	A	(1)	243,758	D
Common Stock	02/15/2025		M		6,625	A	(1)	250,383	D
Common Stock	02/15/2025		M		6,625	A	(1)	257,008	D
Common Stock	02/18/2025		S(2)		4,370	D	$11.963(3)	252,638	D

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
Restricted Stock Unit (RSU)	(1)	02/15/2025		M			1,375	(4)	(5)	Common Stock	1,375	$0	4,125	D
Restricted Stock Unit (RSU)	(1)	02/15/2025		M			2,250	(4)	(5)	Common Stock	2,250	$0	15,750	D
Restricted Stock Unit (RSU)	(1)	02/15/2025		M			6,625	(4)	(5)	Common Stock	6,625	$0	72,875	D
Restricted Stock Unit (RSU)	(1)	02/15/2025		M			6,625	(4)	(5)	Common Stock	6,625	$0	99,375	D

Explanation of Responses:

1. Each Restricted Stock Unit ("RSU") represents a contingent right to receive one share of the Issuer's Common Stock upon settlement for no consideration.

2. The sale of shares is for the sole purpose of covering the Reporting Person's tax liability with respect to the settlement of RSUs.

3. The price reported in Column 4 is a weighted average price. These shares were sold as part of block trades for multiple security holders of the Issuer at prices ranging from $11.86 to $12.18, inclusive. The Reporting Person undertakes to provide to the Issuer, any securityholder 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 within the range set forth herein with regard to the block trade.

4. The RSUs will vest as to 1/16th of the total award in quarterly installments on February 15, May 15, August 15 and November 15, subject to the Reporting Person's provision of service to the Issuer on each vesting date.

5. RSUs do not expire; they either vest or are canceled prior to the vesting date.

	/s/ Charles N. York II	02/21/2025
	** 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 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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