ATAI's three largest insider shareholders as of March 23, 2026 are Investment Group Ltd. Apeiron (TenPercentOwner, 53.41Mn shares), Christian Angermayer (Director, 20.19Mn shares), Cosmo Feilding-Mellen (Director, 7.70Mn shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Investment Group Ltd. Apeiron | 0 | 53,412,414 | 02 Oct, 2025 | |
| Christian Angermayer | 0 | 20,185,200 | 24 Jun, 2021 | |
| Cosmo Feilding-Mellen | 7,702,990 | 0 | 06 Nov, 2025 | |
| Florian Brand | See Remarks | 328,697 | 0 | 20 May, 2024 |
| Srinivas Rao | See Remarks | 212,942 | 0 | 24 Mar, 2025 |
| Anne Nagengast Johnson | Chief Financial Officer | 140,045 | 0 | 24 Mar, 2025 |
| Sahil Kirpekar | Chief Business Officer | 115,636 | 0 | 24 Mar, 2025 |
| Glenn Frank Short | Chief Scientific Officer | 42,333 | 0 | 24 Mar, 2025 |
| Kevin James Craig | Chief Medical Officer | 8,437 | 0 | 24 Mar, 2025 |
| Rosnay Alexis De | 4,666 | 0 | 24 Jun, 2021 | |
| Andrea Heslin Smiley | 4,666 | 0 | 24 Jun, 2021 | |
| Gregory L Weaver | Chief Financial Officer | 4,666 | 0 | 24 Jun, 2021 |
| Amir H Kalali | 4,666 | 0 | 24 Jun, 2021 | |
| Srinivas Rao | See Remarks | 0 | 3,500 | 24 Jun, 2021 |
| Florian Brand | See Remarks | 0 | 2,333 | 24 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 | Cosmo Feilding-Mellen | Stock Option | D | 40,400 | $0.00 | 0 | D | D |
| 25 Nov, 2025 | Cosmo Feilding-Mellen | Stock Option | A | 10,000 | $0.00 | 10,000 | D | A |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Common Shares | A | 7,702,990 | - | 7,702,990 | D | A |
| 05 Nov, 2025 | Robert Hershberg | Stock Option | A | 456,011 | $0.00 | 456,011 | D | A |
| 04 Nov, 2025 | Scott Braunstein | Stock Option | A | 56,818 | $0.00 | 56,818 | D | A |
| 05 Nov, 2025 | Robert Hershberg | Stock Option | A | 97,716 | $0.00 | 97,716 | D | A |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Stock Option | A | 103,000 | $0.00 | 103,000 | D | A |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Stock Option | A | 40,400 | $0.00 | 40,400 | D | A |
| 05 Nov, 2025 | Robert Hershberg | Stock Option | A | 62,394 | $0.00 | 62,394 | D | A |
| 05 Nov, 2025 | Robert Hershberg | Stock Option | A | 103,000 | $0.00 | 103,000 | D | A |
| 01 Oct, 2025 | Christopher Ryan Cave Barrett | Stock Option | A | 175,000 | $0.00 | 175,000 | D | A |
| 30 Sep, 2025 | Investment Group Ltd. Apeiron | Common Shares | A | 2,367,200 | - | 53,412,414 | I | C |
| 30 Sep, 2025 | Investment Group Ltd. Apeiron | Convertible Notes | D | 147,950 | - | 0 | I | C |
| 14 Aug, 2025 | Investment Group Ltd. Apeiron | Common Shares | A | 8,675,799 | $2.19 | 51,045,214 | I | P |
| 13 Aug, 2025 | Srinivas Rao | Stock Option | A | 650,794 | $0.00 | 650,794 | D | A |
| 13 Aug, 2025 | Srinivas Rao | Stock Option | A | 217,777 | $0.00 | 217,777 | D | A |
| 26 Jun, 2025 | Amir H Kalali | Stock Option | A | 103,000 | $0.00 | 103,000 | D | A |
| 26 Jun, 2025 | John Francis Hoffman | Stock Option | A | 206,000 | $0.00 | 206,000 | D | A |
| 26 Jun, 2025 | Laurent Fischer | Stock Option | A | 103,000 | $0.00 | 103,000 | D | A |
| 26 Jun, 2025 | Christian Angermayer | Stock Option | A | 103,000 | $0.00 | 103,000 | D | A |