Alector, Inc.
ALEC- Exchange
- Nasdaq
- Industry
- Biological Products, (No Diagnostic Substances)
- SEC CIK
- 0001653087
In the last 90 days, Alector, Inc. insiders filed 0 open-market purchases and 3 sales; 140 institutions reported holding it in 13F filings for Q2 2026, worth $183.4M in total; no superinvestor holds it.
Holders of 5% or more of ALEC
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Alector, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| TCG Crossover GP II, LLC | 13G | 9.20%10.0M shares | New | Nov 14, 20251 filing | Nov 14, 2025 | SEC |
| Deep Track Capital, LP | 13G | 8.61%12.8M shares | New | Oct 23, 20261 filing | Oct 23, 2026 | SEC |
| Biotechnology Value Fund L P | 13G | 8.40%9.37M shares | New | Sep 18, 20261 filing | Sep 18, 2026 | SEC |
| Rosenthal Arnon | 13G/A | 7.40%8.21M shares | – | Feb 14, 20224 filings | Feb 6, 2026 | SEC |
| BlackRock, Inc. | 13G | 5.20%5.78M shares | +0.50 ppfrom 4.70% | Apr 17, 20254 filings | Apr 27, 2026 | SEC |
| Ra Capital Management, L.P. | 13G | 5.10%7.50M shares | +5.10 ppfrom 0.00% | Dec 6, 20243 filings | Oct 26, 2026 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
47 Schedule 13D and 13G filings on Alector, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Oct 26, 20264:18 PM ET | Ra Capital Management, L.P.and 3 others | 13G | 5.10%7.50M shares | +5.10 ppfrom 0.00% | Oct 19, 2026 | SEC |
| Oct 23, 20264:01 PM ET | Deep Track Capital, LPand 2 others | 13G | 8.61%12.8M shares | New | Oct 16, 2026 | SEC |
| Sep 18, 20264:57 PM ET | Biotechnology Value Fund L Pand 9 others | 13G | 8.40%9.37M shares | New | Sep 11, 2026 | SEC |
| May 14, 20264:57 PM ET | Polaris Venture Partners VI, L.P.and 10 others | 13G/A | 4.70%5.17M shares | −1.80 ppfrom 6.50%Below 5% | Mar 31, 2026 | SEC |
| Apr 27, 20264:12 PM ET | BlackRock, Inc. | 13G | 5.20%5.78M shares | +0.50 ppfrom 4.70% | Mar 31, 2026 | SEC |
| Mar 26, 20263:24 PM ET | Vanguard Group Inc | 13G/A | 0.00%0 shares | −6.32 ppfrom 6.32%Below 5% | Mar 13, 2026 | SEC |
| Feb 17, 20268:23 AM ET | RTW Investments, LPand 1 other | 13G/A | 0.00%0 shares | −6.90 ppfrom 6.90%Below 5% | Dec 31, 2025 | SEC |
| Feb 6, 20264:30 PM ET | Rosenthal Arnon | 13G/A | 7.40%8.21M shares | – | Dec 31, 2025 | SEC |
| Jan 30, 20261:26 PM ET | Vanguard Group Inc | 13G/A | 6.32%6.91M shares | – | Dec 31, 2025 | SEC |
| Jan 21, 202612:30 PM ET | BlackRock, Inc. | 13G/A | 4.70%5.18M shares | −0.40 ppfrom 5.10%Below 5% | Dec 31, 2025 | SEC |
| Nov 14, 20254:18 PM ET | TCG Crossover GP II, LLCand 4 others | 13G | 9.20%10.0M shares | New | Oct 22, 2025 | SEC |
| Nov 14, 20258:18 AM ET | RTW Investments, LPand 1 other | 13G | 6.90%6.99M shares | New | Sep 30, 2025 | SEC |
| Nov 13, 20254:41 PM ET | Polaris Venture Partners VI, L.P.and 10 others | 13G/A | 6.50%7.10M shares | – | Sep 30, 2025 | SEC |
| Nov 7, 202511:13 AM ET | FMR LLCand 1 other | 13G/A | 3.60%3.60M shares | –Below 5% | Oct 31, 2025 | SEC |
| Oct 17, 20256:40 PM ET | BlackRock, Inc. | 13G/A | 5.10%5.20M shares | −1.10 ppfrom 6.20% | Sep 30, 2025 | SEC |
| Aug 14, 20255:54 PM ET | Ra Capital Management, L.P.and 3 others | 13G/A | 0.00%0 shares | –Below 5% | Jun 30, 2025 | SEC |
| Apr 17, 20259:35 AM ET | BlackRock, Inc. | 13G/A | 6.20%6.12M shares | – | Mar 31, 2025 | SEC |
| Dec 6, 2024 | Ra Capital Management, L.P. | 13GOld format | – | New | – | SEC |
| Nov 12, 2024 | Polaris Venture Partners VI, L.P. | 13G/AOld format | – | – | – | SEC |
| Nov 7, 2024 | Morgan Stanley | 13G/AOld format | – | – | – | SEC |
| Feb 13, 2024 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 12, 2024 | Morgan Stanley | 13GOld format | – | New | – | SEC |
| Feb 9, 2024 | Polaris Venture Partners VI, L.P. | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2024 | FMR LLC | 13G/AOld format | – | – | – | SEC |
| Feb 8, 2024 | Rosenthal Arnon | 13GOld format | – | – | – | SEC |
| Jan 24, 20242:27 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Oct 13, 2023 | FMR LLC | 13G/AOld format | – | – | – | SEC |
| Feb 10, 2023 | Rosenthal Arnon | 13G/AOld format | – | – | – | SEC |
| Feb 10, 2023 | EcoR1 Capital, LLC | 13G/AOld format | – | – | – | SEC |
| Feb 9, 202310:29 AM ET | Federated Hermes, Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2023 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2023 | FMR LLC | 13G/AOld format | – | – | – | SEC |
| Feb 7, 2023 | Polaris Venture Partners VI, L.P. | 13G/AOld format | – | – | – | SEC |
| Feb 1, 20239:41 AM ET | Federated Hermes, Inc. | 13G/AOld format | – | – | – | SEC |
| Jan 25, 202310:36 AM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 14, 20221:31 PM ET | Federated Hermes, Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 14, 2022 | Rosenthal Arnon | 13GOld format | – | New | – | SEC |
| Feb 14, 2022 | EcoR1 Capital, LLC | 13G/AOld format | – | – | – | SEC |
| Feb 11, 2022 | Polaris Venture Partners VI, L.P. | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2022 | Vanguard Group Inc | 13G/AOld format | – | – | – | SEC |
| Feb 9, 2022 | FMR LLC | 13GOld format | – | New | – | SEC |
| Feb 3, 20224:29 PM ET | BlackRock Inc. | 13G/AOld format | – | – | – | SEC |
| Jul 12, 2021 | EcoR1 Capital, LLC | 13GOld format | – | New | – | SEC |
| Feb 12, 20211:16 PM ET | Federated Hermes, Inc. | 13G/AOld format | – | – | – | SEC |
| Feb 12, 2021 | Polaris Venture Partners VI, L.P. | 13G/AOld format | – | – | – | SEC |
| Feb 10, 2021 | Vanguard Group Inc | 13GOld format | – | New | – | SEC |
| Feb 2, 20213:13 PM ET | BlackRock Inc. | 13GOld format | – | New | – | SEC |
Form 144: proposed insider sales
65 notices from officers, directors and other affiliates planning to sell Alector, Inc. shares, newest first.
| Filed (ET) | Seller | Shares to sell | Market value | Planned sale | Broker | Filing |
|---|---|---|---|---|---|---|
| Sep 4, 20264:05 PM ET | Grace Wong-SaradOfficer | 3.63K | $9.09K | Sep 4, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Sep 2, 20265:09 PM ET | Grace Wong-SaradOfficer | 656 | $1.80K | Sep 2, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Sep 1, 20268:00 PM ET | Grace Wong-SaradOfficer | 5.66K | $13.6K | Sep 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Sep 1, 20268:00 PM ET | Arnon RosenthalOfficer · Director | 79.7K | $191.3K | Sep 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Sep 1, 20268:00 PM ET | Neil L. BerkleyOfficer | 32.1K | $77.0K | Sep 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jun 3, 20264:23 PM ET | Grace Wong-SaradOfficer | 3.48K | $6.54K | Jun 3, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jun 1, 20267:00 PM ET | Neil L. BerkleyOfficer | 18.2K | $37.7K | Jun 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jun 1, 20267:00 PM ET | Grace Wong-SaradOfficer | 5.24K | $10.8K | Jun 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Jun 1, 20267:00 PM ET | Arnon RosenthalOfficer · Director | 67.6K | $139.9K | Jun 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Apr 16, 20264:31 PM ET | Grace Wong-SaradOfficer | 1.82K | $4.82K | Apr 16, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Mar 10, 20265:16 PM ET | Grace Wong-SaradOfficer | 1.00K | $2.65K | Mar 10, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Mar 3, 20265:08 PM ET | Grace Wong-SaradOfficer | 3.37K | $7.01K | Mar 3, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Feb 27, 20266:10 PM ET | Neil L. BerkleyOfficer | 23.2K | $56.3K | Mar 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Feb 27, 20266:10 PM ET | Arnon RosenthalOfficer · Director | 67.6K | $164.2K | Mar 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Feb 27, 20266:10 PM ET | Grace Wong-SaradOfficer | 6.30K | $15.3K | Mar 2, 2026 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Feb 26, 20264:29 PM ET | Grace Wong-SaradOfficer | 4.08K | $10.2K | Feb 26, 202610b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Dec 5, 20254:09 PM ET | Grace Wong-SaradOfficer | 4.75K | $5.75K | Dec 5, 202510b5-1 | Morgan Stanley Smith Barney LLC Executive Financial Services | SEC |
| Dec 1, 20257:53 PM ET | Arnon RosenthalOfficer · Director | 92.4K | $113.7K | Dec 1, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Dec 1, 20257:50 PM ET | Neil L. BerkleyOfficer | 33.0K | $40.6K | Dec 1, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Dec 1, 20257:49 PM ET | Grace Wong-SaradOfficer | 7.08K | $8.71K | Dec 1, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Dec 1, 20257:48 PM ET | Sara Kenkare-MitraOfficer | 36.9K | $45.4K | Dec 1, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Aug 29, 20256:25 PM ET | Neil L. BerkleyOfficer | 15.4K | $36.3K | Sep 2, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Aug 29, 20256:23 PM ET | Arnon RosenthalOfficer · Director | 50.2K | $118.1K | Sep 2, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Aug 29, 20256:20 PM ET | Grace Wong-SaradOfficer | 5.72K | $13.4K | Sep 2, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
| Aug 29, 20256:17 PM ET | Sara Kenkare-MitraOfficer | 23.0K | $54.1K | Sep 2, 2025 | Morgan Stanley Smith Barney LLC Executive Services | SEC |
Showing the latest 25. See the ALEC notices from the last 12 months