Data spanning the past 90 days through January 10, 2026 reveals that Alector's three principal insider shareholders consist of Director Terrance Mcguire (10.91Mn shares), TenPercentOwner Venture Management Co. Vi, L.L.C. Polaris (9.85Mn shares), Chief Executive Officer Arnon Rosenthal (4.39Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Terrance Mcguire | 10,908,813 | 24 Aug, 2023 | |
| Venture Management Co. Vi, L.L.C. Polaris | 9,853,817 | 31 May, 2024 | |
| Arnon Rosenthal | Chief Executive Officer | 4,392,915 | 03 Dec, 2025 |
| Tillman U. Gerngross | 2,644,319 | 15 Jun, 2023 | |
| Robert King | Chief Development Officer | 550,871 | 04 Oct, 2022 |
| Sara Kenkare-Mitra | President And Head Of R&D | 501,652 | 03 Dec, 2025 |
| Neil Lindsay Berkley | Chief Bus Ofcr & Interim Cfo | 374,309 | 03 Dec, 2025 |
| Gary Romano | Chief Medical Officer | 332,977 | 05 Mar, 2025 |
| Marc Grasso | Chief Financial Officer | 296,072 | 04 Jun, 2025 |
| Robert Paul | Chief Medical Officer | 234,319 | 11 Aug, 2021 |
| Grace Wong-Sarad | Principal Accounting Officer | 122,982 | 08 Dec, 2025 |
| David M. Wehner | 115,330 | 12 Jun, 2024 | |
| Shehnaaz Suliman | President And Coo | 102,598 | 14 Dec, 2021 |
| Louis J Jr Lavigne | 99,409 | 12 Jun, 2025 | |
| Kristine Yaffe | 95,409 | 23 Jun, 2025 | |
| Richard H Scheller | 95,366 | 12 Jun, 2025 | |
| Elizabeth A. Garofalo | 89,950 | 12 Jun, 2025 | |
| Calvin Yu | Vice President And Finance | 76,686 | 07 Jul, 2021 |
| Paula Hammond | 74,909 | 27 Aug, 2025 | |
| Errol B Desouza | 69,950 | 12 Jun, 2025 | |
| Mark Altmeyer | 69,950 | 12 Jun, 2025 |
* 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 |
|---|---|---|---|---|---|---|---|---|
| 05 Dec, 2025 | Grace Wong-Sarad | Common Stock | D | 4,753 | $1.21 | 122,982 | D | S |
| 03 Dec, 2025 | Arnon Rosenthal | Common Stock | D | 104,347 | $1.12 | 2,420,040 | D | S |
| 03 Dec, 2025 | Sara Kenkare-Mitra | Common Stock | D | 41,687 | $1.12 | 501,652 | D | S |
| 03 Dec, 2025 | Grace Wong-Sarad | Common Stock | D | 8,056 | $1.12 | 127,735 | D | S |
| 03 Dec, 2025 | Neil Lindsay Berkley | Common Stock | D | 37,261 | $1.12 | 374,309 | D | S |
| 10 Nov, 2025 | Arnon Rosenthal | Common Stock | A | 174,167 | $0.00 | 2,524,387 | D | A |
| 10 Nov, 2025 | Grace Wong-Sarad | Common Stock | A | 32,343 | $0.00 | 135,791 | D | A |
| 10 Nov, 2025 | Neil Lindsay Berkley | Common Stock | A | 65,000 | $0.00 | 411,570 | D | A |
| 02 Sep, 2025 | Arnon Rosenthal | Common Stock | D | 51,562 | $2.50 | 2,350,220 | D | S |
| 02 Sep, 2025 | Sara Kenkare-Mitra | Common Stock | D | 23,638 | $2.50 | 543,339 | D | S |
| 02 Sep, 2025 | Grace Wong-Sarad | Common Stock | D | 5,910 | $2.50 | 103,448 | D | S |
| 02 Sep, 2025 | Neil Lindsay Berkley | Common Stock | D | 15,842 | $2.50 | 346,570 | D | S |
| 26 Aug, 2025 | Paula Hammond | Common Stock | D | 14,000 | $2.36 | 74,909 | D | S |
| 26 Aug, 2025 | Paula Hammond | - | - | 74,909 | D | |||
| 01 Jul, 2025 | Arnon Rosenthal | Common Stock | A | 137,125 | $0.00 | 2,551,782 | D | A |
| 01 Jul, 2025 | Sara Kenkare-Mitra | Common Stock | A | 54,725 | $0.00 | 566,977 | D | A |
| 20 Jun, 2025 | Kristine Yaffe | Common Stock | D | 1,000 | $1.44 | 95,409 | D | S |
| 11 Jun, 2025 | Errol B Desouza | Common Stock | A | 28,700 | $0.00 | 69,950 | D | A |
| 11 Jun, 2025 | Louis J Jr Lavigne | Common Stock | A | 28,700 | $0.00 | 99,409 | D | A |
| 11 Jun, 2025 | Richard H Scheller | Common Stock | A | 28,700 | $0.00 | 95,366 | D | A |