Alector ALEC Insider Ownership

NASDAQ ALEC
$1.87 -0.05 (-2.60%)
At close: Sep 29, 2026 · 4:00 PM EDT

Insider Holdings by Owner

28.81Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026
Insider Ownership
26.85%
▼-1.23% pp QoQ
Shares Held by Insiders
29.87Mn
filed for Sep 2026
▼-4.39% QoQ
Shares Outstanding
111.22Mn
111,224,116 shares
Direct Holdings
8.16Mn
Indirect: 21.71Mn
Net Shares Traded (QoQ)
-1.37Mn
net selling in Sep 2026
Insiders Holding Shares
19
with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding
Latest —
Average ownership —
Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold
Latest quarter —
Net over range —
Buying quarters —

Insider Ownership Summary

Quarter ending 30 Sep, 2026

As of September 29, 2026, the three largest insider holders of ALEC are Terrance Mcguire (Director, 10.85Mn shares), Venture Management Co. Vi, L.L.C. Polaris (TenPercentOwner, 9.85Mn shares), Tillman U. Gerngross (Director, 2.64Mn shares).

Form 4 Holdings

Insiders Holding ALEC

Insiders 19
Shares held 28.81Mn
Of outstanding 25.90%
# Insider Position Direct Indirect Total Share of Insiders Last Filed
1 Terrance Mcguire Director, TenPercentOwner 0 10,853,817 10,853,817 37.7% 13 Sep, 2023
2 Venture Management Co. Vi, L.L.C. Polaris TenPercentOwner 0 9,853,817 9,853,817 34.2% 31 May, 2024
3 Tillman U. Gerngross Director 2,644,319 0 2,644,319 9.2% 15 Jun, 2023
4 Arnon Rosenthal Chief Executive Officer 2,294,600 0 2,294,600 8.0% 04 Sep, 2026
5 Robert King Chief Development Officer 550,871 0 550,871 1.9% 04 Oct, 2022
6 Sara Kenkare-Mitra President And Head Of Rd 501,652 0 501,652 1.7% 03 Dec, 2025
7 Neil Lindsay Berkley Cfo Chief Business Officer 350,649 0 350,649 1.2% 04 Sep, 2026
8 Gary Romano Chief Medical Officer 332,977 0 332,977 1.2% 05 Mar, 2025
9 Marc Grasso Chief Financial Officer 296,072 0 296,072 1.0% 04 Jun, 2025
10 Richard H Scheller Director 134,899 0 134,899 0.5% 17 Jun, 2026
11 Louis J Jr Lavigne Director 128,109 0 128,109 0.4% 17 Jun, 2026
12 Kristine Yaffe Director 124,109 0 124,109 0.4% 17 Jun, 2026
13 Elizabeth A. Garofalo Director 118,650 0 118,650 0.4% 17 Jun, 2026
14 David M. Wehner Director 115,330 0 115,330 0.4% 12 Jun, 2024
15 Grace Wong-Sarad Principal Accounting Officer 106,015 0 106,015 0.4% 04 Sep, 2026
16 Paula Hammond Director 103,609 0 103,609 0.4% 17 Jun, 2026
17 Shehnaaz Suliman President And Coo 102,598 0 102,598 0.4% 14 Dec, 2021
18 Errol B Desouza Director 98,650 0 98,650 0.3% 17 Jun, 2026
19 Mark Altmeyer Director 98,650 0 98,650 0.3% 17 Jun, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

652 Insider Transactions

Source SEC Form 4
Latest quarter Sep 2026
Download Data
Date Insider Position Transaction Shares Price Value Shares Held After Ownership
03 Sep, 2026 Neil Lindsay Berkley Cfo Chief Business Officer Disposed S 29,251 $2.66 $77.95K 350,649 Direct
02 Sep, 2026 Grace Wong-Sarad Principal Accounting Officer Disposed S 656 $2.75 $1.80K 114,805 Direct
03 Sep, 2026 Arnon Rosenthal Chief Executive Officer Disposed S 72,606 $2.66 $193.47K 2,294,600 Direct
03 Sep, 2026 Grace Wong-Sarad Principal Accounting Officer Disposed S 5,165 $2.67 $13.77K 109,640 Direct
04 Sep, 2026 Grace Wong-Sarad Principal Accounting Officer Disposed S 3,625 $2.51 $9.09K 106,015 Direct
19 Aug, 2026 Arnon Rosenthal Chief Executive Officer Disposed G 1,050,000 $0.00 $0 922,875 Indirect
19 Aug, 2026 Arnon Rosenthal Chief Executive Officer Acquired G 350,000 $0.00 $0 1,002,500 Indirect
19 Aug, 2026 Arnon Rosenthal Chief Executive Officer Acquired G 350,000 $0.00 $0 1,002,500 Indirect
19 Aug, 2026 Arnon Rosenthal Chief Executive Officer Acquired G 350,000 $0.00 $0 1,002,500 Indirect
09 Jul, 2026 Grace Wong-Sarad Principal Accounting Officer Acquired A 20,000 $0.00 $0 115,461 Direct
17 Jun, 2026 Richard H Scheller Director Acquired A 28,700 $0.00 $0 134,899 Direct
17 Jun, 2026 Errol B Desouza Director Acquired A 28,700 $0.00 $0 98,650 Direct
17 Jun, 2026 Mark Altmeyer Director Acquired A 28,700 $0.00 $0 98,650 Direct
17 Jun, 2026 Kristine Yaffe Director Acquired A 28,700 $0.00 $0 124,109 Direct
17 Jun, 2026 Louis J Jr Lavigne Director Acquired A 28,700 $0.00 $0 128,109 Direct
17 Jun, 2026 Paula Hammond Director Acquired A 28,700 $0.00 $0 103,609 Direct
17 Jun, 2026 Elizabeth A. Garofalo Director Acquired A 28,700 $0.00 $0 118,650 Direct
17 Jun, 2026 Mark Altmeyer Director Acquired A 9,450 $0.00 $0 9,450 Direct
17 Jun, 2026 Richard H Scheller Director Acquired A 9,450 $0.00 $0 9,450 Direct
17 Jun, 2026 Kristine Yaffe Director Acquired A 9,450 $0.00 $0 9,450 Direct