Day One Biopharmaceuticals, Inc.
DAWNDelisted Apr 23, 2026- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001845337
Day One Biopharmaceuticals, Inc. was delisted on Apr 23, 2026; its insiders filed their last Form 4 on Apr 27, 2026; 208 institutions reported holding it in 13F filings for Q1 2026, worth $1.85B in total; Soros Fund Management was the only superinvestor holding it.
Open-market trades, last 90 days
Open-market purchases (P) and sales (S) by Day One Biopharmaceuticals, Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.
- Open-market buys
- 0 filings
- Open-market sells
- 0 filings
- Insiders trading
- 0
- Net value
- $0
- Purchases minus sales
Insider roster
Directors, officers and 10% owners who have filed a Form 4 for Day One Biopharmaceuticals, Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.
| Name | Title | Last reported holding | Last filing | Filings, past year |
|---|---|---|---|---|
| Blavatnik Len | 10% Owner | 0 | Apr 27, 2026 | 1 |
| Access Industries Holdings LLC | 10% Owner | 0 | Apr 27, 2026 | 1 |
| Access Industries Management, LLC | 10% Owner | 0 | Apr 27, 2026 | 1 |
| AI Day1 LLC | 10% Owner | 0 | Apr 27, 2026 | 1 |
| Garland J. Scott | Director | – | Apr 23, 2026 | 2 |
| Ramasastry Saira | Director | 0 | Apr 23, 2026 | 2 |
| Holles Natalie C. | Director | 0 | Apr 23, 2026 | 2 |
| Nicholson Garry A | Director | – | Apr 23, 2026 | 2 |
| York Charles N II | COO and CFO | 0 | Apr 23, 2026 | 5 |
| Dable Habib J | Director | – | Apr 23, 2026 | 2 |
| Grossman William | Director | – | Apr 23, 2026 | 2 |
| Vasconcelles Michael | Head of Research and Dev. | 0 | Apr 23, 2026 | 3 |
| Dubow Adam | Gen Counsel & Secretary | 0 | Apr 23, 2026 | 5 |
| Josey John A. | Director | 0 | Apr 23, 2026 | 2 |
| Merendino Lauren | Chief Commercial Officer | 0 | Apr 23, 2026 | 5 |
| Bender Jeremy | CHIEF EXECUTIVE OFFICER | 0Indirect | Apr 23, 2026 | 6 |
| Blackman Samuel C. | HEAD OF R&D | 1,034,015 | Dec 12, 2024 | 0 |
| Gladstone Michael | Director | 766,667Indirect | May 28, 2024 | 0 |
| Becker Daniel J. | Director | – | Jun 26, 2023 | 0 |
| Grant Papanek Julie | Director | 330,000Indirect | Mar 3, 2023 | 0 |
| Atlas Venture Fund XI, L.P. | 10% Owner | 6,008,534 | Dec 14, 2022 | 0 |
| Canaan XI L.P. | 10% Owner | 6,964,301 | Sep 22, 2022 | 0 |
| Canaan Partners XI LLC | 10% Owner | 6,964,301 | Sep 22, 2022 | 0 |
| Atlas Venture Opportunity Fund I, L.P. | 10% Owner | 793,116 | Jul 6, 2022 | 0 |
| Atlas Venture Associates Opportunity I, L.P. | 10% Owner | 766,667 | Jun 22, 2022 | 0 |
| Atlas Venture Associates Opportunity I, LLC | 10% Owner | 766,667 | Jun 22, 2022 | 0 |
| Atlas Venture Associates XI, LLC | 10% Owner | 766,667 | Jun 22, 2022 | 0 |
| Atlas Venture Associates XI, L.P. | 10% Owner | 766,667 | Jun 22, 2022 | 0 |
| Atlas Venture Opportunity Fund II, L.P. | 10% Owner | 766,667 | Jun 22, 2022 | 0 |
| Millennium Pharmaceuticals Inc | 10% Owner | 6,120,124Indirect | Dec 9, 2021 | 0 |
| Takeda Pharmaceutical Co Ltd | 10% Owner | 6,120,124Indirect | Dec 9, 2021 | 0 |
| Takeda Pharmaceuticals U.S.A., Inc. | 10% Owner | 6,120,124Indirect | Dec 9, 2021 | 0 |
| Takeda Ventures, Inc. | 10% Owner | 6,120,124Indirect | Dec 9, 2021 | 0 |
Insider trades
Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| Aug 5, 2024 (view filing)4:01 PM ET | Aug 1 | 4 days | Blavatnik Len and 3 othersOther: Affiliate of 10% Owner | PPurchase | +827.6K | $14.50 | +$12.0M | –827.6K after | Derivative |
| Aug 19, 2024 (view filing) | Aug 16 | 3 days | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −10.7K | $14.00 | −$149.5K | −9.7%98.9K after | |
| Aug 19, 2024 (view filing) | Aug 16 | 3 days | Blackman Samuel C.HEAD OF R&D | SSale | −2.23K | $14.00 | −$31.2K | −0.2%1.13M after | |
| Aug 19, 2024 (view filing) | Aug 16 | 3 days | York Charles N IICOO, CFO AND SECRETARY | SSale | −2.63K | $14.00 | −$36.9K | −1.1%232.5K after | |
| Aug 19, 2024 (view filing) | Aug 16 | 3 days | Dubow AdamGENERAL COUNSEL | SSale | −3.20K | $14.00 | −$44.8K | −10.6%26.9K after | |
| Sep 12, 2024 (view filing) | Sep 10 | 2 days | Blackman Samuel C.HEAD OF R&D | SSale | −30.0K | $14.22 | −$426.6K | −2.7%1.10M after | 10b5-1 |
| Nov 4, 2024 (view filing) | Oct 31 | 4 days | Blackman Samuel C.HEAD OF R&D | SSale | −500 | $16.02 | −$8.01K | 0.0%1.10M after | 10b5-1 |
| Nov 8, 2024 (view filing) | Nov 7 | 1 day | Blackman Samuel C.HEAD OF R&D | SSale | −11.2K | $16.03 | −$180.3K | −1.0%1.09M after | 10b5-1 |
| Nov 12, 2024 (view filing) | Nov 8-11 | 4 days | Blackman Samuel C.HEAD OF R&D | SSale | −28.3K | $16.15 | −$456.2K | −2.6%1.06M after | 2 lots10b5-1 |
| Nov 19, 2024 (view filing) | Nov 18 | 1 day | York Charles N IICOO, CFO AND SECRETARY | SSale | −2.60K | $13.21 | −$34.4K | −1.1%240.1K after | |
| Nov 19, 2024 (view filing) | Nov 18 | 1 day | Dubow AdamGENERAL COUNSEL | SSale | −3.17K | $13.21 | −$41.8K | −9.0%32.2K after | |
| Nov 19, 2024 (view filing) | Nov 18 | 1 day | Blackman Samuel C.HEAD OF R&D | SSale | −2.21K | $13.21 | −$29.1K | −0.2%1.06M after | |
| Nov 19, 2024 (view filing) | Nov 18 | 1 day | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −10.6K | $13.21 | −$139.4K | −8.9%108.4K after | |
| Dec 12, 2024 (view filing) | Dec 10 | 2 days | Blackman Samuel C.HEAD OF R&D | SSale | −30.0K | $13.31 | −$399.3K | −2.8%1.03M after | 10b5-1 |
| Feb 21, 2025 (view filing) | Feb 18 | 3 daysLate | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −12.0K | $11.96 | −$144.1K | −8.6%128.0K after | |
| Feb 21, 2025 (view filing) | Feb 18 | 3 daysLate | Dubow AdamGENERAL COUNSEL | SSale | −4.65K | $11.96 | −$55.6K | −10.5%39.6K after | |
| Feb 21, 2025 (view filing) | Feb 18 | 3 daysLate | York Charles N IICOO, CFO AND SECRETARY | SSale | −4.37K | $11.96 | −$52.3K | −1.7%252.6K after | |
| May 19, 2025 (view filing) | May 16 | 3 days | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −14.0K | $6.26 | −$87.4K | −8.7%145.7K after | |
| May 19, 2025 (view filing) | May 16 | 3 days | York Charles N IICOO, CFO AND SECRETARY | SSale | −4.28K | $6.26 | −$26.8K | −1.6%265.2K after | |
| May 19, 2025 (view filing) | May 16 | 3 days | Dubow AdamGENERAL COUNSEL | SSale | −4.55K | $6.26 | −$28.5K | −8.8%47.1K after | |
| May 19, 2025 (view filing) | May 16 | 3 days | Merendino LaurenChief Commercial Officer | SSale | −3.93K | $6.26 | −$24.6K | −10.0%35.2K after | |
| Aug 19, 2025 (view filing) | Aug 18 | 1 day | Merendino LaurenChief Commercial Officer | SSale | −3.77K | $6.77 | −$25.5K | −8.2%41.9K after | |
| Aug 19, 2025 (view filing) | Aug 18 | 1 day | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −16.1K | $6.77 | −$108.7K | −9.1%161.4K after | |
| Aug 19, 2025 (view filing) | Aug 18 | 1 day | Dubow AdamGen Counsel & Secretary | SSale | −4.37K | $6.77 | −$29.6K | −7.4%54.9K after | |
| Aug 19, 2025 (view filing) | Aug 18 | 1 day | York Charles N IICOO and CFO | SSale | −4.11K | $6.77 | −$27.8K | −1.5%278.0K after | |
| Nov 18, 2025 (view filing) | Nov 17 | 1 day | York Charles N IICOO and CFO | SSale | −4.06K | $8.91 | −$36.2K | −1.4%294.7K after | |
| Nov 18, 2025 (view filing) | Nov 17 | 1 day | Dubow AdamGen Counsel & Secretary | SSale | −4.32K | $8.91 | −$38.5K | −6.5%62.6K after | |
| Nov 18, 2025 (view filing) | Nov 17 | 1 day | Merendino LaurenChief Commercial Officer | SSale | −3.73K | $8.91 | −$33.2K | −6.8%50.8K after | |
| Nov 18, 2025 (view filing) | Nov 17 | 1 day | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −15.9K | $8.91 | −$141.6K | −8.2%177.2K after | |
| Feb 18, 2026 (view filing) | Feb 17 | 1 day | York Charles N IICOO and CFO | SSale | −6.07K | $11.60 | −$70.4K | −1.9%312.0K after | |
| Feb 18, 2026 (view filing) | Feb 17 | 1 day | Vasconcelles MichaelHead of Research and Dev. | SSale | −2.73K | $11.60 | −$31.6K | −38.3%4.40K after | |
| Feb 18, 2026 (view filing) | Feb 17 | 1 day | Dubow AdamGen Counsel & Secretary | SSale | −6.39K | $11.60 | −$74.2K | −8.1%72.7K after | |
| Feb 18, 2026 (view filing) | Feb 17 | 1 day | Merendino LaurenChief Commercial Officer | SSale | −5.81K | $11.60 | −$67.4K | −8.8%60.2K after | |
| Feb 18, 2026 (view filing) | Feb 17 | 1 day | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −15.5K | $11.60 | −$179.3K | −7.0%204.6K after |