Alector ALEC Institutional Ownership

NASDAQ ALEC

$1.83 -0.04 (-2.14%)

At close: Oct 22, 2026 · 4:00 PM EDT

Institutions by Trading Activity

137 Institutions

Increased 72 52.6%

Unchanged 31 22.6%

Reduced 34 24.8%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

81.68%

▲+2.03 pp QoQ

Shares Held by Institutions

91.20Mn

of 111.66Mn outstanding

▲+3.13% QoQ

Shares Outstanding

111.66Mn

20.46Mn held outside 13F filers

Institutional Investors

137

filed 13F for Jun 2026

▲+1 vs prior quarter

Net Shares Added (QoQ)

+2.76Mn

accumulated since last quarter

Value of Holdings

$170.54Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Alector, Inc. (NASDAQ:ALEC) counted 137 institutional investors among its 13F-reported shareholders for the quarter ended June 30, 2026.

These investors held 81.68% of Alector's outstanding shares at the end of Q2 2026, up from 79.65% in Q1 2026.
Total holdings of Alector shares rose 3.13% from Q1 2026, and the number of holders rose 3.79% from Q2 2025.
Of these 137 holders, 72 added to their positions, 34 reduced their stakes and 31 left their positions unchanged.
Combined, institutional investors held 91.2Mn shares of ALEC as of Q2 2026, up 2.76Mn from the prior quarter and up 21.86Mn from a year earlier.
TCG Crossover Management, LLC held the largest position in ALEC at 10Mn shares as of June 30, 2026, or 8.96% of shares outstanding.
The biggest increases in ALEC positions during Q2 2026 came from ADAR1 Capital Management, LLC (+1.83Mn shares), Kynam Capital Management, LP (+1.81Mn shares), Nantahala Capital Management, LLC (+1.5Mn shares), Affinity Asset Advisors, LLC (+1.01Mn shares) and AQR Capital Management LLC (+598.24K shares).
Holders that trimmed the most shares of Alector in Q2 2026 while keeping a position were FMR LLC (-399.71K shares), Jacobs Levy Equity Management, Inc (-388.43K shares), D. E. Shaw & Co., Inc. (-372.85K shares), Renaissance Technologies LLC (-352.52K shares) and Dimensional Fund Advisors LP (-250.09K shares).
Per Business Quant data, the 10 largest holders of Alector at the end of Q2 2026 were TCG Crossover Management, LLC (10Mn shares), BlackRock, Inc. (7.85Mn shares), Acadian Asset Management LLC (4.41Mn shares), Nantahala Capital Management, LLC (4.32Mn shares), Vanguard Capital Management LLC (4.01Mn shares), Kynam Capital Management, LP (3.81Mn shares), Merck & Co., Inc. (3.55Mn shares), Balyasny Asset Management L.P. (3.25Mn shares), 683 Capital Management, LLC (3.2Mn shares) and D. E. Shaw & Co., Inc. (2.96Mn shares).

Form 13F Holdings

137 Institutional Holders

Report period 30 Jun, 2026

Total shares held 91.20Mn

Of outstanding 81.68%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	TCG Crossover Management, LLC	0001839948	10,000,000	8.96%	0	0.00%	$20.10Mn
2	BlackRock, Inc.	0002012383	7,847,879	7.03%	▲106,634	+1.38%	$15.77Mn
3	ACADIAN ASSET MANAGEMENT LLC	0000916542	4,414,345	3.95%	▲375,560	+9.30%	$8.86K
4	Nantahala Capital Management, LLC	0001472322	4,318,109	3.87%	▲1,502,126	+53.34%	$8.68Mn
5	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	4,009,340	3.59%	▲330,618	+8.99%	$8.06Mn
6	Kynam Capital Management, LP	0001907884	3,808,494	3.41%	▲1,808,494	+90.42%	$7.66Mn
7	Merck & Co., Inc.	0000310158	3,545,719	3.18%	0	0.00%	$7.13Mn
8	BALYASNY ASSET MANAGEMENT L.P.	0001218710	3,247,426	2.91%	▲312,173	+10.64%	$6.53Mn
9	683 Capital Management, LLC	0001404574	3,200,000	2.87%	0	0.00%	$6.43Mn
10	D. E. Shaw & Co., Inc.	0001009207	2,959,983	2.65%	▼372,852	-11.19%	$5.95Mn
11	ADAR1 Capital Management, LLC	0001940272	2,883,583	2.58%	▲1,833,583	+174.63%	$5.80Mn
12	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	2,820,493	2.53%	▲236,951	+9.17%	$5.67Mn
13	GEODE CAPITAL MANAGEMENT, LLC	0001214717	2,454,271	2.20%	▲168,053	+7.35%	$4.93Mn
14	Spruce Street Capital LP	0002050194	2,101,068	1.88%	0	0.00%	$4.22Mn
15	MILLENNIUM MANAGEMENT LLC	0001273087	1,988,835	1.78%	▲9,609	+0.49%	$4.00Mn
16	Ikarian Capital, LLC	0001778253	1,982,606	1.78%	▼100,000	-4.80%	$3.99Mn
17	State Street Corp	0000093751	1,879,765	1.68%	▲14,239	+0.76%	$3.78Mn
18	JACOBS LEVY EQUITY MANAGEMENT, INC	0000884414	1,765,929	1.58%	▼388,432	-18.03%	$3.55Mn
19	MEDICI CAPITAL LLC	0001777234	1,652,520	1.48%	0	0.00%	$3.32Mn
20	Affinity Asset Advisors, LLC	0001773195	1,510,000	1.35%	▲1,010,000	+202.00%	$3.04Mn

Showing 1 to 20 of 137 holders