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 |
|---|---|---|---|---|---|---|---|---|---|
| Feb 20, 2024 (view filing) | Feb 16 | 4 days | Blackman Samuel C.HEAD OF RESEARCH AND DEVELOPME | SSale | −2.26K | $15.25 | −$34.4K | −0.2%1.24M after | |
| Feb 20, 2024 (view filing) | Feb 16 | 4 days | Bender JeremyCHIEF EXECUTIVE OFFICER | SSale | −7.62K | $15.25 | −$116.1K | −1.0%721.8K after | |
| Nov 17, 2023 (view filing) | Nov 16 | 1 day | York Charles N IICOO, CFO and Secretary | SSale | −956 | $11.69 | −$11.2K | −0.4%270.2K after | |
| Nov 17, 2023 (view filing) | Nov 16 | 1 day | Dubow AdamGeneral Counsel | SSale | −5.31K | $11.69 | −$62.1K | −31.7%11.4K after | |
| Nov 17, 2023 (view filing) | Nov 16 | 1 day | Blackman Samuel C.Head of Research and Developme | SSale | −709 | $11.69 | −$8.29K | −0.1%1.24M after | |
| Nov 17, 2023 (view filing) | Nov 16 | 1 day | Bender JeremyChief Executive Officer | SSale | −3.11K | $11.69 | −$36.3K | −0.4%709.4K after | |
| Oct 20, 2023 (view filing)4:02 PM ET | Oct 18-20 | 2 days | Blavatnik Len and 3 othersOther: Affiliate of 10% Owner | PPurchase | +1.48M | $10.15 | +$15.0M | +12.9%12.9M after | 3 lots |
| Aug 17, 2023 (view filing) | Aug 17 | Same day | York Charles N IICOO, CFO and Secretary | SSale | −922 | $13.86 | −$12.8K | −0.3%267.5K after | |
| Aug 17, 2023 (view filing) | Aug 17 | Same day | Blackman Samuel C.Head of Research and Developme | SSale | −668 | $13.86 | −$9.26K | −0.1%1.24M after | |
| Aug 17, 2023 (view filing) | Aug 17 | Same day | Bender JeremyChief Executive Officer | SSale | −3.00K | $13.86 | −$41.5K | −0.4%704.2K after | |
| Jun 12, 2023 (view filing)4:03 PM ET | Jun 9 | 3 days | Blavatnik Len and 3 othersOther: Affiliate of 10% Owner | PPurchase | +769.2K | $13.00 | +$10.0M | +7.2%11.5M after | |
| Jun 7, 2023 (view filing) | Jun 5 | 2 days | Blackman Samuel C.Chief Medical Officer | SSale | −1.23K | $16.00 | −$19.7K | −0.1%1.23M after | |
| May 17, 2023 (view filing) | May 16 | 1 day | York Charles N IICOO, CFO and Secretary | SSale | −955 | $13.12 | −$12.5K | −0.4%264.8K after | |
| May 17, 2023 (view filing) | May 16 | 1 day | Blackman Samuel C.Chief Medical Officer | SSale | −692 | $13.12 | −$9.08K | −0.1%1.24M after | |
| May 17, 2023 (view filing) | May 16 | 1 day | Bender JeremyChief Executive Officer | SSale | −3.10K | $13.12 | −$40.7K | −0.3%1.18M after | |
| Mar 14, 2023 (view filing) | Mar 10 | 4 days | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $18.05 | −$180.5K | −0.8%1.23M after | |
| Mar 8, 2023 (view filing) | Mar 7 | 1 day | Bender JeremyChief Executive Officer | SSale | −12.5K | $20.01 | −$250.1K | −1.1%1.17M after | |
| Mar 3, 2023 (view filing) | Mar 1 | 2 days | Grant Papanek JulieDirector | SSale | −25.0K | $18.61 | −$465.3K | −7.0%330.0K after | |
| Feb 21, 2023 (view filing) | Feb 17 | 4 days | York Charles N IICOO, CFO and Secretary | SSale | −9.38K | $20.03 | −$187.8K | −3.5%262.1K after | |
| Feb 17, 2023 (view filing) | Feb 16 | 1 day | York Charles N IICOO, CFO and Secretary | SSale | −930 | $19.57 | −$18.2K | −0.3%271.5K after | |
| Feb 17, 2023 (view filing) | Feb 16 | 1 day | Blackman Samuel C.Chief Medical Officer | SSale | −674 | $19.57 | −$13.2K | −0.1%1.24M after | |
| Feb 17, 2023 (view filing) | Feb 16 | 1 day | Bender JeremyChief Executive Officer | SSale | −3.02K | $19.57 | −$59.1K | −0.3%1.19M after | |
| Feb 13, 2023 (view filing) | Feb 10 | 3 days | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $20.07 | −$200.7K | −0.8%1.24M after | |
| Feb 3, 2023 (view filing) | Feb 1 | 2 days | Grant Papanek JulieDirector | SSale | −25.0K | $21.23 | −$530.8K | −6.6%355.0K after | 2 lots |
| Jan 24, 2023 (view filing) | Jan 23 | 1 day | Bender JeremyChief Executive Officer | SSale | −12.5K | $22.00 | −$275.0K | −1.0%1.18M after | |
| Jan 23, 2023 (view filing) | Jan 20 | 3 days | York Charles N IICOO, CFO and Secretary | SSale | −10.0K | $22.75 | −$227.5K | −3.6%268.8K after | |
| Jan 11, 2023 (view filing) | Jan 10 | 1 day | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $22.86 | −$228.6K | −0.8%1.25M after | 2 lots |
| Jan 4, 2023 (view filing) | Jan 3 | 1 day | Grant Papanek JulieDirector | SSale | −25.0K | $20.65 | −$516.2K | −6.2%380.0K after | 2 lots |
| Dec 22, 2022 (view filing) | Dec 21 | 1 day | Bender JeremyChief Executive Officer | SSale | −12.5K | $20.32 | −$254.0K | −1.0%1.19M after | |
| Dec 22, 2022 (view filing) | Dec 20 | 2 days | York Charles N IICOO, CFO and Secretary | SSale | −10.0K | $20.07 | −$200.7K | −3.5%276.5K after | |
| Dec 12, 2022 (view filing) | Dec 8 | 4 days | Grant Papanek JulieDirector | SSale | −4.36K | $22.08 | −$96.2K | −1.1%405.0K after | |
| Dec 5, 2022 (view filing) | Dec 1-2 | 4 days | Grant Papanek JulieDirector | SSale | −10.0K | $21.65 | −$216.5K | −2.4%409.4K after | 3 lots |
| Dec 5, 2022 (view filing) | Dec 1 | 4 days | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $21.45 | −$214.5K | −0.8%1.26M after | 2 lots |
| Nov 22, 2022 (view filing) | Nov 21 | 1 day | York Charles N IICOO, CFO and Secretary | SSale | −10.0K | $20.76 | −$207.6K | −3.4%286.5K after | 2 lots |
| Nov 22, 2022 (view filing) | Nov 21 | 1 day | Bender JeremyChief Executive Officer | SSale | −12.5K | $20.76 | −$259.5K | −1.0%1.20M after | 2 lots |
| Nov 17, 2022 (view filing) | Nov 16 | 1 day | York Charles N IICOO, CFO and Secretary | SSale | −430 | $21.46 | −$9.23K | −0.1%296.5K after | |
| Nov 17, 2022 (view filing) | Nov 16 | 1 day | Blackman Samuel C.Chief Medical Officer | SSale | −377 | $21.46 | −$8.09K | 0.0%1.27M after | |
| Nov 17, 2022 (view filing) | Nov 16 | 1 day | Bender JeremyChief Executive Officer | SSale | −1.51K | $21.46 | −$32.5K | −0.1%1.22M after | |
| Nov 3, 2022 (view filing) | Nov 1 | 2 days | York Charles N IICOO, CFO and Secretary | SSale | −10.0K | $20.03 | −$200.3K | −3.3%294.4K after | |
| Nov 3, 2022 (view filing) | Nov 1-2 | 2 days | Grant Papanek JulieDirector | SSale | −10.0K | $20.03 | −$200.3K | −2.3%419.4K after | 2 lots |
| Nov 3, 2022 (view filing) | Nov 1 | 2 days | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $20.01 | −$200.1K | −0.8%1.27M after | |
| Nov 3, 2022 (view filing) | Nov 1 | 2 days | Bender JeremyChief Executive Officer | SSale | −12.5K | $20.03 | −$250.4K | −1.0%1.22M after | |
| Oct 5, 2022 (view filing) | Oct 3 | 2 days | York Charles N IICOO, CFO and Secretary | SSale | −10.0K | $20.05 | −$200.5K | −3.2%304.4K after | |
| Oct 5, 2022 (view filing) | Oct 3-4 | 2 days | Grant Papanek JulieDirector | SSale | −10.0K | $20.03 | −$200.3K | −2.3%429.4K after | 2 lots |
| Oct 5, 2022 (view filing) | Oct 3 | 2 days | Blackman Samuel C.Chief Medical Officer | SSale | −10.0K | $19.99 | −$199.9K | −0.8%1.28M after | |
| Oct 5, 2022 (view filing) | Oct 3 | 2 days | Bender JeremyChief Executive Officer | SSale | −12.5K | $20.05 | −$250.6K | −1.0%1.23M after | |
| Sep 22, 2022 (view filing)4:00 PM ET | Sep 21 | 1 day | Canaan XI L.P. and 1 other10% Owner | SSale | −613.6K | $18.55 | −$11.4M | −6.8%8.46M after | 2 lotsDuplicate filing |
| Sep 22, 2022 (view filing) | Sep 21 | 1 day | Grant Papanek JulieDirector | SSale | −613.6K | $18.55 | −$11.4M | −6.8%8.46M after | 2 lots |
| Sep 20, 2022 (view filing)5:47 PM ET | Sep 16-20 | 4 days | Canaan XI L.P. and 1 other10% Owner | SSale | −340.7K | $20.44 | −$6.96M | −3.6%9.08M after | 5 lotsDuplicate filing |
| Sep 20, 2022 (view filing) | Sep 16-20 | 4 days | Grant Papanek JulieDirector | SSale | −340.7K | $20.44 | −$6.96M | −3.6%9.08M after | 5 lots |