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

13F Institutional Holders and Ownership History from Q1 2019 to Q4 2025

Type / Class
Equity / Common Stock, $0.0001 par value
Symbol
ALEC on Nasdaq
Shares outstanding
110,998,986
Price per share
$1.83
All holders as of 31 Dec 2025
Q4 2025
Total 13F shares
84,297,388
Total reported value
$131,464,280
% of total 13F portfolios
0%
Share change
+7,927,108
Value change
-$407,441
Number of holders
127
Price from insider filings
$1.83
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of Alector, Inc. - Common Stock, $0.0001 par value (ALEC) based on Schedule 13D/G filings

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
Polaris Venture Partners VI, L.P. 6.5% $21,001,943 7,095,251 Terrance G. McGuire 30 Sep 2025
VANGUARD GROUP INC 6.3% $10,776,564 6,908,054 The Vanguard Group 31 Dec 2025
BlackRock, Inc. 4.7% -8% $8,080,496 -$33,208 5,179,805 -0.41% BlackRock, Inc. 31 Dec 2025
FMR LLC 3.6% $10,655,467 3,599,820 FMR LLC 31 Oct 2025

As of 31 Dec 2025, 127 institutional investors reported holding 84,297,388 shares of Alector, Inc. - Common Stock, $0.0001 par value (ALEC). This represents 76% of the company’s total 110,998,986 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of Alector, Inc. - Common Stock, $0.0001 par value (ALEC) together control 62% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
TCG Crossover Management, LLC 9% 10,000,000 0.52% $15,600,000
BlackRock, Inc. 6.4% 7,147,766 -0.7% 0% $11,150,515
VANGUARD GROUP INC 6.2% 6,908,054 +14% 0% $10,776,564
Foresite Capital Management IV, LLC 3.5% 3,887,200 2.6% $6,064,032
Merck & Co., Inc. 3.2% 3,545,719 0% 2% $5,531,322
ACADIAN ASSET MANAGEMENT LLC 3.1% 3,442,449 +45% 0.01% $5,362,000
683 Capital Management, LLC 3% 3,350,000 +235% 0.43% $5,226,000
Balyasny Asset Management L.P. 2.9% 3,265,575 0.01% $5,094,297
D. E. Shaw & Co., Inc. 2.1% 2,365,151 +142% 0% $3,689,636
FMR LLC 2% 2,231,171 -85% 0% $3,480,627
JACOBS LEVY EQUITY MANAGEMENT, INC 2% 2,173,202 +77% 0.01% $3,390,195
Ikarian Capital, LLC 1.9% 2,082,606 +174% 0.42% $3,248,866
GEODE CAPITAL MANAGEMENT, LLC 1.9% 2,075,220 +11% 0% $3,238,029
Kynam Capital Management, LP 1.8% 2,000,000 0.2% $3,120,000
STATE STREET CORP 1.6% 1,814,298 +4.6% 0% $2,830,305
RENAISSANCE TECHNOLOGIES LLC 1.4% 1,543,650 +63% 0% $2,408,094
MEDICI CAPITAL LLC 1.4% 1,500,520 +211% 2.6% $2,340,811
MILLENNIUM MANAGEMENT LLC 1.2% 1,332,914 +15% 0% $2,079,346
Euclidean Capital LLC 1.2% 1,307,858 0% 0.55% $2,040,258
MARSHALL WACE, LLP 1.1% 1,166,817 +669% 0% $1,820,234
Spruce Street Capital LP 1% 1,117,986 0% 0.58% $1,744,058
ADAR1 Capital Management, LLC 1% 1,108,000 0.13% $1,728,480
DEERFIELD MANAGEMENT COMPANY, L.P. 0.95% 1,055,192 0% 0.02% $1,646,100
TWO SIGMA INVESTMENTS, LP 0.94% 1,039,656 +238% 0% $1,621,863
DEUTSCHE BANK AG\ 0.93% 1,035,154 -3.1% 0% $1,614,840

Institutional Holders of Alector, Inc. - Common Stock, $0.0001 par value (ALEC) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 84,297,388 $131,464,280 -$407,441 $1.56 127
2025 Q3 74,753,370 $221,270,645 +$17,828,827 $2.96 147
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
2020 Q1 47,897,578 $1,155,708,612 +$264,293,053 $24.13 102
2019 Q4 37,073,169 $638,772,713 +$44,393,449 $17.23 81
2019 Q3 34,671,437 $499,972,276 +$80,611,697 $14.42 74
2019 Q2 29,064,816 $551,259,295 +$7,378,322 $19.00 63
2019 Q1 27,527,687 $515,314,000 +$515,304,000 $18.72 53