Day One Biopharmaceuticals, Inc. (DAWN) Insider Ownership

Historic Insider Ownership Trends

DAWN's three largest insider shareholders as of March 23, 2026 are Xi L.P. Canaan (TenPercentOwner, 6.96Mn shares), Pharmaceutical Co Ltd Takeda (TenPercentOwner, 6.12Mn shares), Venture Fund Xi, L.P. Atlas (TenPercentOwner, 6.01Mn shares).

Top Direct Holders

Insider ownership data is derived from the last 60 months of Form 4 SEC filings.
Holder Position Shares (Direct) Shares (Indirect) Report Date
Xi L.P. Canaan 6,964,301 0 22 Sep, 2022
Pharmaceutical Co Ltd Takeda 0 6,120,124 09 Dec, 2021
Venture Fund Xi, L.P. Atlas 6,008,534 0 14 Dec, 2022
Samuel C. Blackman Head Of Rd 1,034,015 0 12 Dec, 2024
Samuel C. Blackman Chief Medical Officer 0 1,000,000 03 Dec, 2021
Venture Opportunity Fund I, L.P. Atlas 793,116 0 06 Jul, 2022
Venture Opportunity Fund Ii, L.P. Atlas 766,667 0 22 Jun, 2022
Michael Gladstone 0 766,667 22 Jun, 2022
Julie Papanek Grant 0 330,000 03 Mar, 2023
Charles N Ii York Coo And Cfo 312,025 0 18 Feb, 2026
Jeremy Bender Chief Executive Officer 204,603 0 18 Feb, 2026
Adam Dubow Gen Counsel Secretary 72,694 0 18 Feb, 2026
John A. Josey 72,292 0 01 Jun, 2021
Lauren Merendino Chief Commercial Officer 60,157 0 18 Feb, 2026
Saira Ramasastry 40,485 0 21 Jun, 2024
Daniel J. Becker 5,000 0 01 Jun, 2021
Michael Vasconcelles Head Of Research And Dev. 4,397 0 18 Feb, 2026

* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.

Recent Insider Transactions

Detailed insider trading activity based on Form 4 SEC filings.
Download Data
Transaction Date Insider Name Security Class Transaction Type Shares Traded Price Shares Remaining Ownership Code
15 Feb, 2026 Charles N Ii York Common Stock A 2,250 - 296,965 D M
15 Feb, 2026 Lauren Merendino Common Stock A 3,162 - 53,971 D M
15 Feb, 2026 Adam Dubow Common Stock A 2,963 - 65,589 D M
15 Feb, 2026 Michael Vasconcelles Common Stock A 7,125 - 7,125 D M
15 Feb, 2026 Jeremy Bender Common Stock A 4,750 - 181,915 D M
15 Feb, 2026 Adam Dubow Common Stock A 1,750 - 67,339 D M
15 Feb, 2026 Jeremy Bender Common Stock A 11,688 - 193,603 D M
15 Feb, 2026 Lauren Merendino Common Stock A 3,688 - 57,659 D M
17 Feb, 2026 Michael Vasconcelles Common Stock D 2,728 $11.60 4,397 D S
15 Feb, 2026 Charles N Ii York Common Stock A 6,625 - 303,590 D M
15 Feb, 2026 Michael Vasconcelles Restricted Stock Unit (RSU) D 7,125 $0.00 106,875 D M
15 Feb, 2026 Jeremy Bender Common Stock A 11,687 - 205,290 D M
15 Feb, 2026 Charles N Ii York Common Stock A 6,625 - 310,215 D M
15 Feb, 2026 Adam Dubow Common Stock A 3,688 - 71,027 D M
15 Feb, 2026 Lauren Merendino Common Stock A 3,687 - 61,346 D M
15 Feb, 2026 Jeremy Bender Common Stock A 14,812 - 220,102 D M
15 Feb, 2026 Charles N Ii York Common Stock A 7,875 - 318,090 D M
15 Feb, 2026 Lauren Merendino Common Stock A 4,625 - 65,971 D M
15 Feb, 2026 Adam Dubow Common Stock A 3,687 - 74,714 D M
15 Feb, 2026 Adam Dubow Common Stock A 4,375 - 79,089 D M