| Date | Name | Symbol | Type | Security | Shares | Price | Value | Ownership | Reported |
| 01/17/2023 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | | 70.1k | $4.70 | $329.5k | | 01/17/2023 |
| 01/17/2023 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | Common Stock | 11.7k | $0.00 | $0 | | 01/17/2023 |
| 04/26/2022 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | | 75k | $9.51 | $713.2k | | 04/26/2022 |
| 02/22/2022 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $7.85 | $31.4k | | 02/22/2022 |
| 02/04/2022 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $7.97 | $31.9k | | 02/04/2022 |
| 01/24/2022 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $9.84 | $39.4k | | 01/24/2022 |
| 01/04/2022 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $17.12 | $68.5k | | 01/04/2022 |
| 12/22/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $16.36 | $65.4k | | 12/22/2021 |
| 12/14/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | | 85k | $15.73 | $1.3M | | 12/14/2021 |
| 12/06/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $16.35 | $65.4k | | 12/06/2021 |
| 11/22/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $18.09 | $72.4k | | 11/22/2021 |
| 11/04/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $27.54 | $110.2k | | 11/04/2021 |
| 10/22/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $25.94 | $103.8k | | 10/22/2021 |
| 10/04/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $28.78 | $115.1k | | 10/04/2021 |
| 09/22/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $30.82 | $123.3k | | 09/22/2021 |
| 09/07/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $32.03 | $128.1k | | 09/07/2021 |
| 08/23/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $28.60 | $114.4k | | 08/23/2021 |
| 08/04/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $33.72 | $134.9k | | 08/04/2021 |
| 07/06/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $34.15 | $136.6k | | 07/06/2021 |
| 06/22/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $36.17 | $144.7k | | 06/22/2021 |
| 06/04/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $33.48 | $133.9k | | 06/04/2021 |
| 05/24/2021 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 4k | $35.61 | $142.4k | | 05/24/2021 |
| 12/15/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | | 72.4k | $53.88 | $3.9M | | 12/15/2020 |
| 05/14/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 28.2k | $36.03 | $1M | | 05/13/2020 |
| 05/14/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 37.8k | $36.03 | $1.4M | By Investeringsselskabet G.H. ApS | 05/13/2020 |
| 05/13/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 19.2k | $37.88 | $728.4k | By Investeringsselskabet G.H. ApS | 05/13/2020 |
| 05/13/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Sale | Common Stock | 14.7k | $37.86 | $557.5k | | 05/13/2020 |
| 01/07/2020 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | Employee Stock Option (right to buy) | 130k | $30.34 | $3.9M | | 01/07/2020 |
| 12/11/2018 | Y-mAbs Therapeutics, Inc. | YMAB | Grant | Employee Stock Option (right to buy) | 107.5k | $21.97 | $2.4M | | 12/11/2018 |