Alector, Inc.
US ˙ NasdaqGS ˙ US0144421072

SecurityALEC / Alector, Inc.
InstitutionNorthern Trust Corp
Latest Disclosed Ownership692,256 shares
Latest Disclosed Value $ 1,488,351
Northern Trust Corp reports 17.80% increase in ownership of ALEC / Alector, Inc.

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 692,256 shares of Alector, Inc. (US:ALEC) valued at $1,488,350 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 587,653 shares of Alector, Inc.. This represents a change in shares of 17.80% during the quarter. The current value of the position is $1,252,983 USD.

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)
2026-05-14 2026-03-31 13F ALECTOR COM 014442107 692,256 104,603 17.80 1,488 62.45 0.0002
2026-02-17 2025-12-31 13F ALECTOR COM 014442107 587,653 -46,056 -7.27 917 -51.15 0.0001
2025-11-14 2025-09-30 13F ALECTOR COM 014442107 633,709 -24,452 -3.72 1,876 103.58 0.0002
2025-08-13 2025-06-30 13F ALECTOR COM 014442107 658,161 -39,068 -5.60 921 7.47 0.0001
2025-05-13 2025-03-31 13F ALECTOR COM 014442107 697,229 -62,645 -8.24 858 -40.32 0.0001
2025-02-14 2024-12-31 13F ALECTOR COM 014442107 759,874 40,291 5.60 1,436 -57.17 0.0002
2024-11-13 2024-09-30 13F ALECTOR COM 014442107 719,583 70,855 10.92 3,353 13.85 0.0005
2024-08-14 2024-06-30 13F ALECTOR COM 014442107 648,728 -21,495 -3.21 2,945 -27.00 0.0005
2024-05-14 2024-03-31 13F ALECTOR COM 014442107 670,223 55,667 9.06 4,035 -17.74 0.0007
2024-02-13 2023-12-31 13F ALECTOR COM 014442107 614,556 -21,509 -3.38 4,904 19.00 0.0009
2023-11-13 2023-09-30 13F ALECTOR COM 014442107 636,065 20,198 3.28 4,122 11.35 0.0008
2023-08-11 2023-06-30 13F ALECTOR COM 014442107 615,867 18,526 3.10 3,701 0.11 0.0007
2023-05-15 2023-03-31 13F ALECTOR COM 014442107 597,341 9,694 1.65 3,698 -31.83 0.0007
2023-02-13 2022-12-31 13F ALECTOR COM 014442107 587,647 -6,160 -1.04 5,424 -3.47 0.0011
2022-11-14 2022-09-30 13F ALECTOR COM 014442107 593,807 -2,186 -0.37 5,618 -7.22 0.0013
2022-08-12 2022-06-30 13F ALECTOR COM 014442107 595,993 11,519 1.97 6,055 -27.29 0.0013
2022-05-13 2022-03-31 13F ALECTOR COM 014442107 584,474 -17,512 -2.91 8,328 -33.01 0.0015
2022-02-08 2021-12-31 13F ALECTOR COM 014442107 601,986 -4,611 -0.76 12,431 -10.20 0.0020
2021-11-15 2021-09-30 13F ALECTOR COM 014442107 606,597 -10,251 -1.66 13,843 7.74 0.0025
2021-08-13 2021-06-30 13F ALECTOR COM 014442107 616,848 67,404 12.27 12,849 16.10 0.0023
2021-05-12 2021-03-31 13F ALECTOR COM 014442107 549,444 -28,087 -4.86 11,067 26.64 0.0021
2021-02-11 2020-12-31 13F ALECTOR COM 014442107 577,531 -18,686 -3.13 8,739 39.13 0.0017
2020-11-16 2020-09-30 13F ALECTOR COM 014442107 596,217 -3,686 -0.61 6,281 -57.16 0.0014
2020-08-14 2020-06-30 13F ALECTOR COM 014442107 599,903 148,103 32.78 14,662 34.49 0.0035
2020-05-14 2020-03-31 13F ALECTOR COM 014442107 451,800 61,975 15.90 10,902 62.33 0.0031
2020-02-14 2019-12-31 13F ALECTOR COM 014442107 389,825 15,780 4.22 6,716 24.51 0.0015
2019-11-13 2019-09-30 13F ALECTOR COM 014442107 374,045 274,268 274.88 5,394 184.64 0.0013
2019-08-13 2019-06-30 13F ALECTOR COM 014442107 99,777 -380 -0.38 1,895 1.12 0.0004
2019-05-13 2019-03-31 13F ALECTOR COM 014442107 100,157 100,157 1,874 0.0005
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.