Atai Beckley's top three insider shareholders as of September 29, 2026 are Investment Group Ltd. Apeiron (TenPercentOwner, 53.41Mn shares), Cosmo Feilding-Mellen (Director, 7.70Mn shares), Cosmo Feilding-Mellen (Director, 7.66Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Investment Group Ltd. Apeiron | TenPercentOwner | 0 | 53,412,414 | 53,412,414 | 86.2% | 02 Oct, 2025 |
| 2 | Cosmo Feilding-Mellen | Director | 7,702,990 | 0 | 7,702,990 | 12.4% | 06 Nov, 2025 |
| 3 | Florian Brand | Officer | 328,697 | 0 | 328,697 | 0.5% | 20 May, 2024 |
| 4 | Srinivas Rao | Officer | 212,942 | 0 | 212,942 | 0.3% | 24 Mar, 2025 |
| 5 | Anne Nagengast Johnson | Chief Financial Officer | 140,045 | 0 | 140,045 | 0.2% | 24 Mar, 2025 |
| 6 | Sahil Kirpekar | Chief Business Officer | 115,636 | 0 | 115,636 | 0.2% | 24 Mar, 2025 |
| 7 | Glenn Frank Short | Chief Scientific Officer | 42,333 | 0 | 42,333 | 0.1% | 24 Mar, 2025 |
| 8 | Kevin James Craig | Chief Medical Officer | 8,437 | 0 | 8,437 | 0.0% | 24 Mar, 2025 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 25 Nov, 2025 | Cosmo Feilding-Mellen | Director | Disposed D | 40,400 | $0.00 | $0 | 0 | Direct |
| 25 Nov, 2025 | Cosmo Feilding-Mellen | Director | Acquired A | 10,000 | $0.00 | $0 | 10,000 | Direct |
| 04 Nov, 2025 | Scott Braunstein | Director | Acquired A | 56,818 | $0.00 | $0 | 56,818 | Direct |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Director | Acquired A | 7,702,990 | — | — | 7,702,990 | Direct |
| 05 Nov, 2025 | Robert Hershberg | Director | Acquired A | 456,011 | $0.00 | $0 | 456,011 | Direct |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Director | Acquired A | 103,000 | $0.00 | $0 | 103,000 | Direct |
| 05 Nov, 2025 | Robert Hershberg | Director | Acquired A | 97,716 | $0.00 | $0 | 97,716 | Direct |
| 05 Nov, 2025 | Robert Hershberg | Director | Acquired A | 62,394 | $0.00 | $0 | 62,394 | Direct |
| 05 Nov, 2025 | Cosmo Feilding-Mellen | Director | Acquired A | 40,400 | $0.00 | $0 | 40,400 | Direct |
| 05 Nov, 2025 | Robert Hershberg | Director | Acquired A | 103,000 | $0.00 | $0 | 103,000 | Direct |
| 01 Oct, 2025 | Christopher Ryan Cave Barrett | Officer | Acquired A | 175,000 | $0.00 | $0 | 175,000 | Direct |
| 30 Sep, 2025 | Investment Group Ltd. Apeiron | TenPercentOwner | Acquired C | 2,367,200 | — | — | 53,412,414 | Indirect |
| 30 Sep, 2025 | Investment Group Ltd. Apeiron | TenPercentOwner | Disposed C | 147,950 | — | — | 0 | Indirect |
| 14 Aug, 2025 | Investment Group Ltd. Apeiron | TenPercentOwner | Acquired P | 8,675,799 | $2.19 | $19.00Mn | 51,045,214 | Indirect |
| 13 Aug, 2025 | Srinivas Rao | Officer | Acquired A | 650,794 | $0.00 | $0 | 650,794 | Direct |
| 13 Aug, 2025 | Srinivas Rao | Officer | Acquired A | 217,777 | $0.00 | $0 | 217,777 | Direct |
| 26 Jun, 2025 | Christian Angermayer | Director, TenPercentOwner | Acquired A | 103,000 | $0.00 | $0 | 103,000 | Direct |
| 26 Jun, 2025 | Amir H Kalali | Director | Acquired A | 103,000 | $0.00 | $0 | 103,000 | Direct |
| 26 Jun, 2025 | Laurent Fischer | Director | Acquired A | 103,000 | $0.00 | $0 | 103,000 | Direct |
| 26 Jun, 2025 | John Francis Hoffman | Director | Acquired A | 206,000 | $0.00 | $0 | 206,000 | Direct |