Charles N. York II - May 26, 2021 Form 3 Insider Report for Day One Biopharmaceuticals, Inc. (DAWN)

Role: COO, CFO and Secretary
Signature: /s/ Charles N. York II
Stock symbol: DAWN
Transactions as of: May 26, 2021
Transactions value $: $0
Form type: 3
Date filed: 5/26/2021, 08:58 PM
Next filing: Jan 20, 2022

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	DAWN	Common Stock						338K	May 26, 2021	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	DAWN	Stock Option (right to buy Common Stock)							May 26, 2021	Common Stock	237K	$16.00	Direct	F2
holding	DAWN	Stock Option (right to buy Common Stock)							May 26, 2021	Common Stock	260K	$16.00	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Certain of the shares are subject to the Issuer's right of repurchase if underlying vesting conditions are not met.
F2	The option vests as to 25% of the total shares on February 25, 2022 and then 2.0833% of the total shares vest monthly thereafter, with 100% of the total shares vested on February 25, 2025, subject to the Reporting Person's provision of service to the Issuer on each vesting date.
F3	The option vests as to 25% of the total shares on May 23, 2022 and then 2.0833% of the total shares vest monthly thereafter, with 100% of the total shares vested on May 23, 2025, subject to the Reporting Person's provision of service to the Issuer on each vesting date.