Form
SCHEDULE 13G/A
Passive or exempt beneficial ownership filing.
Polaris Venture Partners VI, L.P. - 31 Mar 2026 SCHEDULE 13G/A Report for Alector, Inc. Common Stock, $0.0001 par value per share (ALEC)
- Filing manager
- Polaris Venture Partners VI, L.P.
- Reporting owner
- Terrance G. McGuire
- Beneficially owned shares
- 5,173,499 shares
- Large-stake signal
-
Ownership
4.7%Beneficial ownership of this reported class.
Shares
5,173,499 sharesShares beneficially owned as disclosed.
Event date
31 Mar 2026Date tied to the ownership event or amendment.
Accepted by SEC
14 May 2026EDGAR acceptance date.
How to read this large-stake filing
- Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
- Compare this filing with the holder history and issuer page before treating the percentage as a current position.
- Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
- Class ownership
- 4.7%
- Symbol
- ALEC
- Shares outstanding
- 110,074,447 shares
- SEC form
- SCHEDULE 13G/A
- Accepted by SEC
- 14 May 2026, 16:57:27 UTC
- Event date
- 31 Mar 2026
- Prior SEC filing
- 13 Nov 2025
- Source filing
- View source filing
Ownership signal
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Subject security
Names, identifiers, and filing context for this profile.
2 source fields
Source evidence
Original filing metadata and source links for verification.
5 source fields
Key filing fact
Polaris Venture Partners VI, L.P. disclosed 4.7% ownership in Alector, Inc. Common Stock, $0.0001 par value per share (ALEC) on 31 Mar 2026.
Key facts
- Polaris Venture Partners VI, L.P. filed SCHEDULE 13G/A for Alector, Inc. Common Stock, $0.0001 par value per share (ALEC).
- Disclosed ownership: 4.7%.
- Date of event: 31 Mar 2026.
Change
- Previous schedule filing date: 13 Nov 2025.
- Current filing was accepted on 14 May 2026, 16:57.
Research use
- This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
- Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.
Evidence
Backed by Schedule 13D/13G
View source filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting persons
Disclosed reporting parties (11)
Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.
| Name | Ownership | Shares owned | Sole voting power | Shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Polaris Venture Partners VI, L.P. | 0.5% | 498,468 | 498,468 | 0 | /s/ Lauren Crockett | Lauren Crockett/ Authorized Signatory of Polaris Venture Management Co. VI, L.L.C., general partner of Polaris Venture Partners VI, L.P. | |
| Polaris Venture Partners Founders' Fund VI, L.P. | 0.2% | 267,979 | 267,979 | 0 | /s/ Lauren Crockett | Lauren Crockett/ Authorized Signatory of Polaris Venture Management Co. VI, L.L.C., GP of Polaris Venture Partners Founders' Fund VI, L.P. | |
| Polaris Venture Partners VI (AIV), L.P. | 3% | 3,280,842 | 3,280,842 | 0 | /s/ Lauren Crockett | Lauren Crockett/ Authorized Signatory of Polaris Venture Management Co. VI, L.L.C., general partner of Polaris Venture Partners VI (AIV), L.P. | |
| Polaris Venture Partners VI (AIV-B), L.P. | 0.7% | 806,528 | 806,528 | 0 | /s/ Lauren Crockett | Lauren Crockett/ Authorized Signatory of Polaris Venture Management Co. VI, L.L.C., general partner of Polaris Venture Partners VI (AIV-B), L.P. | |
| Polaris Venture Management Co VI, L.L.C. | 4.4% | 4,853,817 | 0 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Authorized Signatory* | |
| David Barrett | 4.4% | 4,853,817 | 0 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact | |
| Brian Chee | 4.4% | 4,853,817 | 0 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact | |
| Jonathan A. Flint | 4.4% | 4,892,941 | 39,124 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact | |
| Terrance G. McGuire | 4.7% | 5,173,499 | 319,682 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact | |
| Amir Nashat | 4.5% | 4,985,149 | 131,332 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact | |
| Bryce Youngren | 4.4% | 4,865,681 | 11,864 | 4,853,817 | /s/ Lauren Crockett | Lauren Crockett/ Attorney-In-Fact |
CIK / CUSIP context first