Security Snapshot

Alector, Inc. - Common Stock, $0.0001 par value per share (ALEC) Institutional Ownership

CUSIP: 014442107

13F Institutional Holders and Ownership History from Q1 2019 to Q2 2026

Latest Period

Q2 2026

Institutions Reporting

141

Shares (Excl. Options)

91,241,723

Price

$2.01

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Latest holder snapshot 5 signals
Portfolio coverage rank
0%
Share change
+2,873,660
Value change
+$5,148,101
Number of holders
141
Issuer context Names, identifiers, and filing context for this profile. 3 identity fields
Shares outstanding
110,074,447
SEC-reported price per share
$1.52
Insider filing price
$1.52
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors

Key facts

  • ALEC - Alector, Inc. - Common Stock, $0.0001 par value per share is tracked under CUSIP 014442107.
  • 141 institutions reported positions in Q2 2026.
  • 5 significant owners is listed from Schedule 13D/13G reporting.

Change

  • Holder count moved from 138 to 141 between Q1 2026 and Q2 2026.
  • SEC-reported value moved from $189,989,177 to $183,395,271.

Research use

  • You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
  • 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.

Evidence

Source: SEC Form 13F

Latest holder context comes from 141 institutions filings for Q2 2026.

Open SEC evidence

Security key

014442107

Latest holder period

Q2 2026

13F holders

141

13D/G owners

5

CIK / CUSIP context first

13D/G owners

Significant owners

Large-stake holder rows connected to Schedule 13D/G evidence.

Rows
5
Security
ALEC
Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
TCG Crossover GP II, LLC 9.2% $29,600,000 10,000,000 Chen Yu 22 Oct 2025
Rosenthal Arnon 7.4% $12,813,723 8,213,925 Arnon Rosenthal 31 Dec 2025
BlackRock, Inc. 5.2% +10% $12,436,060 +$1,299,479 5,784,214 +12% BlackRock, Inc. 31 Mar 2026
Polaris Venture Partners VI, L.P. 4.7% -26% $12,157,723 -$4,516,117 5,173,499 -27% Terrance G. McGuire 31 Mar 2026
FMR LLC 3.6% $10,655,467 3,599,820 FMR LLC 31 Oct 2025

As of 30 Jun 2026, 141 institutional investors reported holding 91,241,723 shares of Alector, Inc. - Common Stock, $0.0001 par value per share (ALEC). This represents 83% of the company’s total 110,074,447 outstanding shares.

13F concentration

Top 25 institutional shareholders

Largest 13F positions for this security by reported shares and value.

Top holder share
68%
Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
TCG Crossover Management, LLC 9.1% 10,000,000 0% 0.48% $20,100,000
BlackRock, Inc. 7.1% 7,847,879 +1.4% 0% $15,774,236
ACADIAN ASSET MANAGEMENT LLC 4% 4,414,345 +9.3% 0.01% $8,863,000
Nantahala Capital Management, LLC 3.9% 4,318,109 +53% 0.52% $8,679,399
VANGUARD CAPITAL MANAGEMENT LLC 3.6% 4,009,340 +9% 0% $8,058,773
Kynam Capital Management, LP 3.5% 3,808,494 +90% 0.42% $7,655,073
Merck & Co., Inc. 3.2% 3,545,719 0% 1.4% $7,126,896
Balyasny Asset Management L.P. 3% 3,247,426 +11% 0.01% $6,527,326
683 Capital Management, LLC 2.9% 3,200,000 0% 0.59% $6,432,000
D. E. Shaw & Co., Inc. 2.7% 2,959,983 -11% 0% $5,949,566
ADAR1 Capital Management, LLC 2.6% 2,883,583 +175% 0.27% $5,796,002
VANGUARD PORTFOLIO MANAGEMENT LLC 2.6% 2,820,493 +9.2% 0% $5,669,191
GEODE CAPITAL MANAGEMENT, LLC 2.2% 2,454,271 +7.4% 0% $4,934,077
Spruce Street Capital LP 1.9% 2,101,068 0% 0.83% $4,223,147
MILLENNIUM MANAGEMENT LLC 1.8% 1,988,835 +0.49% 0% $3,997,558
Ikarian Capital, LLC 1.8% 1,982,606 -4.8% 0.66% $3,985,038
STATE STREET CORP 1.7% 1,879,765 +0.76% 0% $3,778,328
JACOBS LEVY EQUITY MANAGEMENT, INC 1.6% 1,765,929 -18% 0.01% $3,549,517
MEDICI CAPITAL LLC 1.5% 1,652,520 0% 6.5% $3,321,565
Affinity Asset Advisors, LLC 1.4% 1,510,000 +202% 0.15% $3,035,100
Eversept Partners, LP 1.3% 1,423,873 +5.4% 0.16% $2,861,985
FMR LLC 1.3% 1,396,398 -22% 0% $2,806,759
AQR CAPITAL MANAGEMENT LLC 1.2% 1,309,577 +84% 0% $2,632,249
Euclidean Capital LLC 1.2% 1,307,858 0% 0.6% $2,628,795
MACKENZIE FINANCIAL CORP 1% 1,109,770 +29% 0% $2,230,638

Quarter history

Institutional holders across reporting periods

Holder count, reported shares/value, and median price by quarter.

Periods
30
Latest
Q2 2026
Rows shown
1-25 of 30
Period 13F Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q2 91,241,723 $183,395,271 +$5,148,101 $2.01 141
2026 Q1 88,395,892 $189,989,177 +$10,033,251 $2.15 138
2025 Q4 84,346,669 $131,541,158 -$373,194 $1.56 130
2025 Q3 74,741,672 $221,236,018 +$17,794,200 $2.96 146
2025 Q2 70,504,594 $98,716,242 -$652,478 $1.40 134
2025 Q1 72,505,139 $89,184,395 -$1,704,057 $1.23 139
2024 Q4 73,449,099 $138,781,190 -$36,884,482 $1.89 147
2024 Q3 72,547,576 $338,388,962 -$1,018,637 $4.66 158
2024 Q2 72,687,195 $329,955,349 -$13,884,915 $4.54 157
2024 Q1 74,200,085 $446,678,675 +$61,253,193 $6.02 156
2023 Q4 63,928,176 $510,115,302 +$16,550,304 $7.98 144
2023 Q3 62,119,605 $402,563,158 +$20,670,443 $6.48 145
2023 Q2 58,985,239 $354,496,843 +$4,367,360 $6.01 142
2023 Q1 58,273,875 $360,651,817 +$17,929,999 $6.19 144
2022 Q4 54,844,285 $506,217,126 -$5,426,867 $9.23 154
2022 Q3 54,578,353 $516,264,248 +$5,671,869 $9.46 162
2022 Q2 53,817,727 $546,756,104 -$17,438,158 $10.16 148
2022 Q1 55,399,462 $789,780,092 -$5,073,123 $14.25 159
2021 Q4 54,728,224 $1,130,142,954 +$66,134,357 $20.65 160
2021 Q3 52,231,382 $1,191,926,737 +$72,825,941 $22.82 144
2021 Q2 49,168,688 $1,024,647,606 +$63,360,607 $20.83 133
2021 Q1 46,154,577 $929,480,793 +$13,141,895 $20.14 123
2020 Q4 46,284,829 $700,229,278 -$61,389,553 $15.13 130
2020 Q3 49,519,452 $522,137,542 -$50,083,788 $10.54 136
2020 Q2 50,099,049 $1,223,842,967 +$53,677,644 $24.44 133
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