0001950047-24-003270.txt : 20240501 0001950047-24-003270.hdr.sgml : 20240501 20240501162250 ACCESSION NUMBER: 0001950047-24-003270 CONFORMED SUBMISSION TYPE: 144 PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20240501 DATE AS OF CHANGE: 20240501 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: Day One Biopharmaceuticals, Inc. CENTRAL INDEX KEY: 0001845337 STANDARD INDUSTRIAL CLASSIFICATION: PHARMACEUTICAL PREPARATIONS [2834] ORGANIZATION NAME: 03 Life Sciences IRS NUMBER: 832415215 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: 144 SEC ACT: 1933 Act SEC FILE NUMBER: 001-40431 FILM NUMBER: 24903386 BUSINESS ADDRESS: STREET 1: 2000 SIERRA POINT PARKWAY, SUITE 501 CITY: BRISBANE STATE: CA ZIP: 94005 BUSINESS PHONE: 650 484-0899 MAIL ADDRESS: STREET 1: 2000 SIERRA POINT PARKWAY, SUITE 501 CITY: BRISBANE STATE: CA ZIP: 94005 FORMER COMPANY: FORMER CONFORMED NAME: Day One Biopharmaceuticals Holding Co LLC DATE OF NAME CHANGE: 20210209 REPORTING-OWNER: COMPANY DATA: COMPANY CONFORMED NAME: Bender Jeremy CENTRAL INDEX KEY: 0001863107 ORGANIZATION NAME: FILING VALUES: FORM TYPE: 144 MAIL ADDRESS: STREET 1: 395 OYSTER POINT BLVD. STREET 2: SUITE 217 CITY: SOUTH SAN FRANCISCO STATE: CA ZIP: 94080 144 1 primary_doc.xml 144 0001863107 XXXXXXXX LIVE 0001845337 DAY ONE BIOPHARMACEUTICALS INC 001-40431 2000 Sierra Point Parkway Suite 501 Brisbane CA 94005 6504840899 JEREMY BENDER Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

120000 2052000.00 87384856 05/01/2024 NASDAQ Common 09/06/2023 Restricted Stock Awards Issuer N 120000 09/06/2023 N/A N JEREMY BENDER

2000 Sierra Point Parkway Suite 501 Brisbane CA 94005

Common 02/16/2024 7615 116128.75 The securities to be sold were acquired upon the vesting of restricted stock units during the period of 9/1/2021 through 9/6/2023 05/01/2024 10/03/2023 /s/ Jeremy Bender