As of November 6, 2026, Alector, Inc. is a publicly traded company (Nasdaq: ALEC); its largest reported holder is Chen Yu, with 9.2% on Schedule 13G of November 14, 2025, then Deep Track Capital (8.61%). The largest insider holding is Arnon Rosenthal, the chief executive and a director, with 3,514,600 shares (2.4% of shares outstanding), per Form 4 of October 15, 2026 (Schedule 13G, November 14, 2025).
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Is Alector, Inc. a real, registered company?
- Alector, Inc. files with the SEC under CIK 1653087 (its SEC filings).
- Its shares are listed under the ticker ALEC on Nasdaq (SEC company record).
- business address in South San Francisco, California, as its SEC filings state.
- Court and bankruptcy records: see Before you sign or pay below.
Before you sign or pay
- Court and bankruptcy: No federal court case or bankruptcy filing found under Alector, Inc. in our court records and SEC 8-K records (as of 2026-11-06).
- Layoffs: 1 exit or restructuring plan reported on Form 8-K, Item 2.05 (latest filed 2025-10-21, about 75 jobs).
- Ownership: 5%+ holders are reported on Schedule 13D or 13G; the latest names RA Capital (filed 2026-10-26).
Who are Alector, Inc.'s owners and officers?
Alector, Inc.: business address in South San Francisco, California; industry Biological Products, (No Diagnostic Substances) (Schedule 13G, 2026-10-26).
| Report | Holder | Share |
|---|---|---|
| Schedule 13G, 2026-10-26 | Ra Capital Management, L.P. | 5.1% |
| Schedule 13G, 2026-10-23 | Deep Track Capital, LP | 8.61% |
| Schedule 13G, 2026-09-18 | Bvf Partners L P/Il | 8.4% |
| Schedule 13G/A, 2026-05-14 | Terrance G. Mcguire | 4.7% |
| Schedule 13G, 2026-04-27 | Blackrock, Inc. | 5.2% |
| Schedule 13G/A, 2026-03-26 | The Vanguard Group | 0% |
| Schedule 13G/A, 2026-02-17 | Rtw Investments, LP | 0% |
| Schedule 13G/A, 2026-02-06 | Arnon Rosenthal | 7.4% |
| Schedule 13G/A, 2026-01-30 | The Vanguard Group | 6.32% |
| Schedule 13G/A, 2026-01-21 | Blackrock, Inc. | 4.7% |
| Schedule 13G, 2025-11-14 | Rtw Investments, LP | 6.9% |
| Schedule 13G, 2025-11-14 | Chen Yu | 9.2% |
Questions about who owns Alector, Inc.
Who owns Alector, Inc.?
On this page, 6 holders' latest ownership filings report 5% or more of Alector, Inc.: Chen Yu (9.2%, Schedule 13G, filed 2025-11-14), Deep Track Capital, LP (8.61%, Schedule 13G, filed 2026-10-23), Bvf Partners L P/Il (8.4%, Schedule 13G, filed 2026-09-18), Arnon Rosenthal (7.4%, Schedule 13G/A, filed 2026-02-06) and Blackrock, Inc. (5.2%, Schedule 13G, filed 2026-04-27); 1 more is listed above.
Who are the largest shareholders of Alector, Inc.?
By the share each holder's latest filing reports, the largest holders of Alector, Inc. on this page are Chen Yu (9.2%), Deep Track Capital, LP (8.61%) and Bvf Partners L P/Il (8.4%).
When did Chen Yu buy into Alector, Inc.?
The filings give report dates, not purchase dates. The earliest filing from Chen Yu on this page is the Schedule 13G, filed 2025-11-14, reporting 9.2%.
Is this an audit or a full list?
Neither. The ownership list on this page covers only Schedule 13D and 13G filings, which holders make once they own 5% or more of a class of shares (an amendment can report a stake that has since fallen below 5%); 12 such filings are shown here. It is not an audit and not a full cap table: holders who never reached 5% are not listed, and a stake can change after its latest filing.
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What the Full Report on Alector, Inc. covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
19 cited sources found
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Which insiders own Alector, Inc. shares?
Directors, officers and holders of 10% or more report their shares on Forms 3, 4 and 5. Each line is the latest such report, largest holding first.
- , the chief executive and a director: 3,514,600 shares (2.4% of shares outstanding), 2,512,100 held directly and 1,002,500 indirectly (Form 4, 2026-10-15).
- , the president and head of r: 501,652 shares (0.34% of shares outstanding) (Form 4, 2025-12-03).
- , the chief financial officer and amp: 395,216 shares (0.27% of shares outstanding) (Form 4, 2026-10-15).
- , the chief medical officer: 332,977 shares (0.22% of shares outstanding) (Form 4, 2025-03-05).
- , the chief financial officer: 296,072 shares (0.20% of shares outstanding) (Form 4, 2025-06-04).
Shares outstanding: 148,877,074 as of 2026-10-30, from the company's latest SEC cover page.
How much has Alector, Inc. raised?
No fundraising or offering filing from Alector, Inc. is on file with us.
Red flags found
1 exit or restructuring plan on Form 8-K (latest Form 8-K, 2025-10-21).
Keep reading
More on Alector, Inc. and the records around it.
Alector, Inc. elsewhere on the record
- 5%+ stake filings Oct 2026
- Layoff notices Oct 2025
Companies that share a holder
- TCG Crossover GP II, LLC also filed stake reports on 21 other companies: ALX Oncology Holdings Inc. (Aug 2026), First Tracks Biotherapeutics, Inc. (Aug 2026), Fulcrum Therapeutics, Inc. (Aug 2026)
- RTW Investments, LP also filed stake reports on 43 other companies: CG Oncology, Inc. (Aug 2026), iRhythm Holdings, Inc. (Aug 2026), Kailera Therapeutics, Inc. (Aug 2026)
- BIOTECHNOLOGY VALUE FUND L P also filed stake reports on 55 other companies: Frazier Life Sciences Acquisition Corp. II (Oct 2026), Olema Pharmaceuticals, Inc. (Oct 2026), Foghorn Therapeutics Inc. (Oct 2026)
Related pages
Filings, cases and notices link to their records. A not-found line names the records searched; it is not proof of absence.
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https://mentionfox.com/who-owns/alector