| Date | Name | Symbol | Type | Security | Shares | Price | Value | Ownership | Reported |
| 08/17/2023 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 3k | $13.86 | $41.5k | | 08/15/2023 |
| 08/15/2023 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 3.6k | $0.00 | $0 | | 08/15/2023 |
| 08/15/2023 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 4.8k | $0.00 | $0 | | 08/15/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Other (disposition) | Common Stock | 240.3k | $0.00 | $0 | | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Other (acquisition) | Common Stock | 240.3k | $0.00 | $0 | By Melissa Claire Bender | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 240.3k | $0.00 | $0 | | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 240.3k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 240.3k | $0.00 | $0 | By Melissa Claire Bender | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 240.3k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 59.7k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 59.7k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 29.9k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 07/01/2023 | Day One Biopharmaceuticals, Inc. | | Gift | Common Stock | 29.9k | $0.00 | $0 | See Footnote | 07/01/2023 |
| 05/16/2023 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 3.1k | $13.12 | $40.7k | | 05/15/2023 |
| 05/15/2023 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 3.6k | $0.00 | $0 | | 05/15/2023 |
| 05/15/2023 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 4.8k | $0.00 | $0 | | 05/15/2023 |
| 03/07/2023 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.5k | $20.01 | $250.1k | | 03/07/2023 |
| 01/23/2023 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.5k | $22.00 | $275k | | 01/23/2023 |
| 01/17/2023 | Day One Biopharmaceuticals, Inc. | | Grant | Stock Option (right to buy Common Stock) | 244k | $20.87 | $5.1M | | 01/17/2023 |
| 01/17/2023 | Day One Biopharmaceuticals, Inc. | | Grant | Restricted Stock Units | 76k | $0.00 | $0 | | 01/17/2023 |
| 11/21/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.1k | $20.74 | $250.9k | | 11/21/2022 |
| 11/21/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 400 | $21.38 | $8.6k | | 11/21/2022 |
| 11/16/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 1.5k | $21.46 | $32.5k | | 11/15/2022 |
| 11/15/2022 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 3.6k | $0.00 | $0 | | 11/15/2022 |
| 11/01/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.5k | $20.03 | $250.4k | | 11/01/2022 |
| 10/03/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.5k | $20.05 | $250.6k | | 10/03/2022 |
| 09/01/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 10.6k | $23.15 | $246.4k | | 09/01/2022 |
| 09/01/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 1.9k | $23.79 | $44.2k | | 09/01/2022 |
| 09/01/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 10.6k | $23.15 | $246.4k | | 09/01/2022 |
| 09/01/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 1.9k | $23.79 | $44.2k | | 09/01/2022 |
| 08/16/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 4k | $24.31 | $97.3k | | 08/15/2022 |
| 08/15/2022 | Day One Biopharmaceuticals, Inc. | | Exercise | Restricted Stock Units | 10.7k | $0.00 | $0 | | 08/15/2022 |
| 08/04/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 12.5k | $20.00 | $250k | | 08/04/2022 |
| 07/18/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 2.6k | $20.00 | $52k | | 07/18/2022 |
| 07/08/2022 | Day One Biopharmaceuticals, Inc. | | Sale | Common Stock | 1.8k | $20.00 | $35.9k | | 07/08/2022 |
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