Alector, Inc.
US ˙ NasdaqGS ˙ US0144421072

SecurityALEC / Alector, Inc.
InstitutionVanguard Group Inc
Latest Disclosed Ownership0 shares
Ownership 0.00%
Vanguard Group Inc ownership in ALEC / Alector, Inc.

2026-03-26 - Vanguard Group Inc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 0 shares of Alector, Inc. (US:ALEC). This represents 0.0 percent ownership of the company. In their previous filing dated 2026-01-30 , Vanguard Group Inc had reported owning 6,908,054 shares, indicating a decrease of -100.00 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date
Effective
Date
Form Prev
Shares
Latest
Shares
ΔShares
(Percent)
Ownership
(Percent)
ΔOwnership
(Percent)
2026-03-26 2026-03-26 13G/A 6,908,054 0 -100.00 0.00 -100.00
2026-01-30 2026-01-30 13G/A 4,386,541 6,908,054 57.48 6.32 21.31
2024-02-13 2024-02-13 13G/A 6,364,611 4,386,541 -31.08 5.21 -32.34
2023-02-09 2023-02-09 13G/A 5,540,240 6,364,611 14.88 7.70 12.90
2022-02-09 2022-02-09 13G/A 5,002,859 5,540,240 10.74 6.82 8.08
2021-02-10 2021-02-10 13G 5,002,859 6.31

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-01-29 2025-12-31 13F ALECTOR COM 014442107 6,908,054 873,395 14.47 10,777 -39.67 0.0002
2025-11-07 2025-09-30 13F ALECTOR COM 014442107 6,034,659 46,955 0.78 17,863 113.10 0.0003
2025-08-11 2025-06-30 13F ALECTOR COM 014442107 5,987,704 -65,337 -1.08 8,383 12.59 0.0001
2025-05-09 2025-03-31 13F ALECTOR COM 014442107 6,053,041 436,662 7.77 7,445 -29.86 0.0001
2025-02-11 2024-12-31 13F ALECTOR COM 014442107 5,616,379 160,652 2.94 10,615 -58.25 0.0002
2024-11-13 2024-09-30 13F ALECTOR COM 014442107 5,455,727 134,757 2.53 25,424 5.24 0.0005
2024-08-13 2024-06-30 13F ALECTOR COM 014442107 5,320,970 408,392 8.31 24,157 -18.31 0.0005
2024-05-10 2024-03-31 13F ALECTOR COM 014442107 4,912,578 526,037 11.99 29,574 -15.52 0.0006
2024-03-11 2023-12-31 13F/A-1 ALECTOR COM 014442107 4,386,541 -1,134,367 -20.55 35,005 -2.16 0.0008
2024-02-14 2023-12-31 13F ALECTOR COM 014442107 4,386,541 -1,134,367 35,005 0.0007
2023-12-18 2023-09-30 13F/A-1 ALECTOR COM 014442107 5,520,908 -1,107,318 -16.71 35,775 -10.19 0.0009
2023-11-14 2023-09-30 13F ALECTOR COM 014442107 5,520,908 -1,107,318 35,775 0.0002
2023-08-14 2023-06-30 13F ALECTOR COM 014442107 6,628,226 224,063 3.50 39,836 0.49 0.0009
2023-07-14 2023-03-31 13F/A-1 ALECTOR COM 014442107 6,404,163 39,552 0.62 39,642 -32.52 0.0010
2023-05-15 2023-03-31 13F ALECTOR COM 014442107 6,404,163 39,552 39,642 0.0010
2023-02-10 2022-12-31 13F ALECTOR COM 014442107 6,364,611 611,417 10.63 58,745 7.94 0.0016
2022-11-14 2022-09-30 13F ALECTOR COM 014442107 5,753,194 44,498 0.78 54,426 -6.16 0.0016
2022-08-12 2022-06-30 13F ALECTOR COM 014442107 5,708,696 264,773 4.86 58,000 -25.23 0.0016
2022-05-13 2022-03-31 13F ALECTOR COM 014442107 5,443,923 -96,317 -1.74 77,576 -32.19 0.0018
2022-02-14 2021-12-31 13F ALECTOR COM 014442107 5,540,240 462,807 9.11 114,406 -1.26 0.0026
2021-11-12 2021-09-30 13F ALECTOR COM 014442107 5,077,433 146,113 2.96 115,867 12.80 0.0029
2021-08-13 2021-06-30 13F ALECTOR COM 014442107 4,931,320 -238,219 -4.61 102,719 -1.34 0.0026
2021-05-14 2021-03-31 13F ALECTOR COM 014442107 5,169,539 166,680 3.33 104,114 37.55 0.0028
2021-02-12 2020-12-31 13F ALECTOR COM 014442107 5,002,859 120,857 2.48 75,692 47.17 0.0022
2020-11-16 2020-09-30 13F ALECTOR COM 014442107 4,882,002 32,841 0.68 51,432 -56.60 0.0017
2020-08-14 2020-06-30 13F ALECTOR COM 014442107 4,849,161 539,724 12.52 118,514 13.97 0.0042
2020-05-15 2020-03-31 13F ALECTOR COM 014442107 4,309,437 1,620,807 60.28 103,986 124.47 0.0044
2020-02-14 2019-12-31 13F ALECTOR COM 014442107 2,688,630 390,119 16.97 46,326 39.77 0.0016
2019-11-14 2019-09-30 13F ALECTOR COM 014442107 2,298,511 1,389,501 152.86 33,144 91.91 0.0012
2019-08-14 2019-06-30 13F ALECTOR COM 014442107 909,010 43,274 5.00 17,271 6.57 0.0006
2019-05-15 2019-03-31 13F ALECTOR COM 014442107 865,736 865,736 16,206 0.0006
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.