Alector ALEC Institutional Ownership

NASDAQ ALEC

$1.85 -0.02 (-1.07%)

At close: Sep 30, 2026 · 4:00 PM EDT

Institutions by Trading Activity

138 Institutions

Increased 72 52.2%

Unchanged 32 23.2%

Reduced 34 24.6%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

82.73%

▲+2.77 pp QoQ

Shares Held by Institutions

92.02Mn

of 111.22Mn outstanding

▲+9.70% QoQ

Shares Outstanding

111.22Mn

19.21Mn held outside 13F filers

Institutional Investors

138

filed 13F for Jun 2026

▲+1 vs prior quarter

Net Shares Added (QoQ)

+8.14Mn

accumulated since last quarter

Value of Holdings

$170.23Mn

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

Quarter ending 30 Jun, 2026

Alector, Inc. (NASDAQ:ALEC) has 138 institutional investors that have filed 13F reports for the period ending June 2026.

These investors held 82.7% of outstanding shares in June 2026, up from 80.0% in March 2026.
They increased total shares held in ALEC by 9.7% quarter over quarter, and investors in Alector increased 3.76% from a year ago.
Of these 138 holders, 72 added to their stakes in Alector, 34 trimmed positions, and 32 made no changes.
Combined, these investors held 92.02Mn shares in ALEC for June 2026, up by 8.14Mn shares quarter on quarter, and up 22.68Mn shares year over year.
As of June 30, 2026, TCG Crossover Management, LLC held the largest stake in Alector with 10.0Mn shares, accounting for 8.99% of total shares outstanding.
Leading buyers of Alector shares for the quarter ending June 2026 were ADAR1 Capital Management, LLC (1.83Mn), Kynam Capital Management, LP (1.81Mn), Nantahala Capital Management, LLC (1.5Mn), Affinity Asset Advisors, LLC (1.01Mn), Sixth Street Partners Management Company, L.P. (818.83K).
Leading sellers of Alector shares for the quarter ending June 2026 were FMR LLC (399.71K), JACOBS LEVY EQUITY MANAGEMENT, INC (388.43K), D. E. Shaw & Co., Inc. (372.85K), RENAISSANCE TECHNOLOGIES LLC (352.52K), DIMENSIONAL FUND ADVISORS LP (250.09K).
Business Quant data shows the 10 biggest positions in Alector as of June 2026 are held by TCG Crossover Management, LLC (10.0Mn), BlackRock, Inc. (7.85Mn), ACADIAN ASSET MANAGEMENT LLC (4.41Mn), Nantahala Capital Management, LLC (4.32Mn), VANGUARD CAPITAL MANAGEMENT LLC (4.01Mn), Kynam Capital Management, LP (3.81Mn), Merck & Co., Inc. (3.55Mn), BALYASNY ASSET MANAGEMENT L.P. (3.25Mn), 683 Capital Management, LLC (3.2Mn), D. E. Shaw & Co., Inc. (2.96Mn).

Form 13F Holdings

138 Institutional Holders

Report period 30 Jun, 2026

Total shares held 92.02Mn

Of outstanding 82.73%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	TCG Crossover Management, LLC	0001839948	10,000,000	8.99%	0	0.00%	$20.10Mn
2	BlackRock, Inc.	0002012383	7,847,879	7.06%	▲106,634	+1.38%	$15.77Mn
3	ACADIAN ASSET MANAGEMENT LLC	0000916542	4,414,345	3.97%	▲375,560	+9.30%	$8.86K
4	Nantahala Capital Management, LLC	0001472322	4,318,109	3.88%	▲1,502,126	+53.34%	$8.68Mn
5	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	4,009,340	3.60%	▲330,618	+8.99%	$8.06Mn
6	Kynam Capital Management, LP	0001907884	3,808,494	3.42%	▲1,808,494	+90.42%	$7.66Mn
7	Merck & Co., Inc.	0000310158	3,545,719	3.19%	0	0.00%	$7.13Mn
8	BALYASNY ASSET MANAGEMENT L.P.	0001218710	3,247,426	2.92%	▲312,173	+10.64%	$6.53Mn
9	683 Capital Management, LLC	0001404574	3,200,000	2.88%	0	0.00%	$6.43Mn
10	D. E. Shaw & Co., Inc.	0001009207	2,959,983	2.66%	▼372,852	-11.19%	$5.95Mn
11	ADAR1 Capital Management, LLC	0001940272	2,883,583	2.59%	▲1,833,583	+174.63%	$5.80Mn
12	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	2,820,493	2.54%	▲236,951	+9.17%	$5.67Mn
13	GEODE CAPITAL MANAGEMENT, LLC	0001214717	2,454,271	2.21%	▲168,053	+7.35%	$4.93Mn
14	Spruce Street Capital LP	0002050194	2,101,068	1.89%	0	0.00%	$4.22Mn
15	MILLENNIUM MANAGEMENT LLC	0001273087	1,988,835	1.79%	▲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	1.69%	▲14,239	+0.76%	$3.78Mn
18	JACOBS LEVY EQUITY MANAGEMENT, INC	0000884414	1,765,929	1.59%	▼388,432	-18.03%	$3.55Mn
19	MEDICI CAPITAL LLC	0001777234	1,652,520	1.49%	0	0.00%	$3.32Mn
20	Affinity Asset Advisors, LLC	0001773195	1,510,000	1.36%	▲1,010,000	+202.00%	$3.04Mn

Showing 1 to 20 of 138 holders