According to recent filings covering the 90 days ending December 12, 2025, the three most significant insider holders at Day One Biopharmaceuticals are COO And Cfo Charles N Ii York (294.71K shares), Chief Executive Officer Jeremy Bender (177.16K shares), Gen Counsel & Secretary Adam Dubow (62.63K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Day1 Llc Ai | 12,929,322 | 20 Oct, 2023 | |
| Xi L.P. Canaan | 6,964,301 | 22 Sep, 2022 | |
| Pharmaceutical Co Ltd Takeda | 6,120,124 | 09 Dec, 2021 | |
| Venture Fund Xi, L.P. Atlas | 6,008,534 | 14 Dec, 2022 | |
| Samuel C. Blackman | Head Of R&D | 2,034,015 | 12 Dec, 2024 |
| Venture Opportunity Fund I, L.P. Atlas | 793,116 | 06 Jul, 2022 | |
| Michael Gladstone | 766,667 | 22 Jun, 2022 | |
| Venture Opportunity Fund Ii, L.P. Atlas | 766,667 | 22 Jun, 2022 | |
| Julie Papanek Grant | 330,000 | 03 Mar, 2023 | |
| Charles N Ii York | COO And Cfo | 294,715 | 18 Nov, 2025 |
| Jeremy Bender | Chief Executive Officer | 177,165 | 18 Nov, 2025 |
| John A. Josey | 72,292 | 01 Jun, 2021 | |
| Adam Dubow | Gen Counsel & Secretary | 62,626 | 18 Nov, 2025 |
| Lauren Merendino | Chief Commercial Officer | 50,809 | 18 Nov, 2025 |
| Saira Ramasastry | 40,485 | 21 Jun, 2024 | |
| Daniel J. Becker | 5,000 | 01 Jun, 2021 |
* 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.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 25 Nov, 2025 | Jeremy Bender | Common Stock | D | 300,000 | $0.00 | 1,108,285 | I | G |
| 25 Nov, 2025 | Jeremy Bender | Common Stock | A | 300,000 | $0.00 | 300,000 | I | G |
| 25 Nov, 2025 | Jeremy Bender | Common Stock | D | 300,000 | $0.00 | 808,285 | I | G |
| 25 Nov, 2025 | Jeremy Bender | Common Stock | A | 300,000 | $0.00 | 300,000 | I | G |
| 25 Nov, 2025 | Jeremy Bender | Common Stock | D | 7,225 | $0.00 | 7,225 | I | G |
| 25 Nov, 2025 | Jeremy Bender | Common Stock | D | 7,225 | $0.00 | 0 | I | G |
| 15 Nov, 2025 | Jeremy Bender | Common Stock | A | 3,570 | - | 164,935 | D | M |
| 15 Nov, 2025 | Adam Dubow | Common Stock | A | 2,963 | - | 57,821 | D | M |
| 15 Nov, 2025 | Lauren Merendino | Common Stock | A | 3,162 | - | 47,161 | D | M |
| 15 Nov, 2025 | Charles N Ii York | Common Stock | A | 1,375 | - | 283,277 | D | M |
| 15 Nov, 2025 | Charles N Ii York | Common Stock | A | 2,250 | - | 285,527 | D | M |
| 15 Nov, 2025 | Adam Dubow | Common Stock | A | 1,750 | - | 59,571 | D | M |
| 15 Nov, 2025 | Jeremy Bender | Common Stock | A | 4,750 | - | 169,685 | D | M |
| 15 Nov, 2025 | Lauren Merendino | Common Stock | A | 3,687 | - | 50,848 | D | M |
| 15 Nov, 2025 | Charles N Ii York | Common Stock | A | 6,625 | - | 292,152 | D | M |
| 15 Nov, 2025 | Adam Dubow | Common Stock | A | 3,687 | - | 63,258 | D | M |
| 15 Nov, 2025 | Lauren Merendino | Common Stock | A | 3,687 | - | 54,535 | D | M |
| 15 Nov, 2025 | Jeremy Bender | Common Stock | A | 11,687 | - | 181,372 | D | M |
| 15 Nov, 2025 | Jeremy Bender | Common Stock | A | 11,687 | - | 193,059 | D | M |
| 15 Nov, 2025 | Adam Dubow | Common Stock | A | 3,687 | - | 66,945 | D | M |