Alector, Inc.
US ˙ NasdaqGS ˙ US0144421072

SecurityALEC / Alector, Inc.
InstitutionDeerfield Management Company, L.p. (series C)
Latest Disclosed Ownership1,055,192 shares
Latest Disclosed Value $ 2,268,663
Deerfield Management Company, L.p. (series C) ownership in ALEC / Alector, Inc.

On May 15, 2026 - Deerfield Management Company, L.p. (series C) filed a 13F-HR form disclosing ownership of 1,055,192 shares of Alector, Inc. (US:ALEC) valued at $2,268,663 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 1,055,192 shares of Alector, Inc.. This represents a change in shares of 0.00% during the quarter. The current value of the position is $1,872,966 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)
2026-05-15 2026-03-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 2,269 37.79 0.0268
2026-02-17 2025-12-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 1,646 -47.29 0.0210
2025-11-14 2025-09-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 3,123 111.44 0.0477
2025-08-14 2025-06-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 1,477 13.88 0.0268
2025-05-15 2025-03-31 13F ALECTOR COM 014442107 1,055,192 -11,770 -1.10 1,298 -35.66 0.0256
2025-02-14 2024-12-31 13F ALECTOR COM 014442107 1,066,962 11,770 1.12 2,017 -59.00 0.0382
2024-11-14 2024-09-30 13F ALECTOR COM 014442107 1,055,192 -93,134 -8.11 4,917 -5.68 0.0735
2024-08-14 2024-06-30 13F ALECTOR COM 014442107 1,148,326 75,481 7.04 5,213 -19.28 0.0867
2024-05-15 2024-03-31 13F ALECTOR COM 014442107 1,072,845 5,035 0.47 6,459 -24.21 0.1124
2024-02-14 2023-12-31 13F ALECTOR COM 014442107 1,067,810 12,618 1.20 8,521 24.63 0.1573
2023-11-14 2023-09-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 6,838 7.82 0.1506
2023-08-14 2023-06-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 6,342 -2.91 0.1354
2023-05-15 2023-03-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 6,532 -32.94 0.1456
2023-02-14 2022-12-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 9,739 -2.43 0.2016
2022-11-14 2022-09-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 9,982 -6.89 0.1987
2022-08-15 2022-06-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 10,721 -28.70 0.2211
2022-05-16 2022-03-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 15,036 -31.00 0.3362
2022-02-14 2021-12-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 21,790 -9.51 0.4570
2021-11-15 2021-09-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 24,079 9.55 0.4699
2021-08-16 2021-06-30 13F ALECTOR COM 014442107 1,055,192 0 0.00 21,980 3.43 0.3904
2021-05-17 2021-03-31 13F ALECTOR COM 014442107 1,055,192 0 0.00 21,252 33.12 0.4466
2021-02-16 2020-12-31 13F ALECTOR COM 014442107 1,055,192 -406,786 -27.82 15,965 3.66 0.3155
2020-12-30 2020-09-30 13F/A-1 ALECTOR COM 014442107 1,461,978 -215,019 -12.82 15,402 -62.42 0.3750
2020-11-16 2020-09-30 13F ALECTOR COM 014442107 1,461,978 -215,019 15,402 375,026.1145
2020-08-14 2020-06-30 13F ALECTOR COM 014442107 1,676,997 -62,000 -3.57 40,986 -2.33 1.1936
2020-05-15 2020-03-31 13F ALECTOR COM 014442107 1,738,997 -337,815 -16.27 41,962 17.27 1.3317
2020-02-14 2019-12-31 13F ALECTOR COM 014442107 2,076,812 0 0.00 35,783 19.48 1.1417
2019-11-14 2019-09-30 13F ALECTOR COM 014442107 2,076,812 329,889 18.88 29,948 -9.77 1.2210
2019-08-14 2019-06-30 13F ALECTOR COM 014442107 1,746,923 -210,000 -10.73 33,192 -9.40 1.1923
2019-05-15 2019-03-31 13F ALECTOR COM 014442107 1,956,923 1,956,923 36,634 1.4048
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.