Arnon Rosenthal - 10 Nov 2025 Form 4 Insider Report for Alector, Inc. (ALEC)

Role
Chief Executive Officer, Director
Signature
/s/ Grace Wong-Sarad, by power of attorney
Issuer symbol
ALEC
Transactions as of
10 Nov 2025
Net transactions value
$0
Form type
4
Filing time
12 Nov 2025, 16:10:27 UTC
Previous filing
04 Sep 2025
Next filing
03 Dec 2025
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Rosenthal Arnon Chief Executive Officer, Director C/O ALECTOR, INC., 131 OYSTER POINT BLVD, SUITE 600, SOUTH SAN FRANCISCO /s/ Grace Wong-Sarad, by power of attorney 12 Nov 2025 0001757770

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ALEC Common Stock Award $0 +174,167 +7.4% $0.000000 2,524,387 10 Nov 2025 Direct F1
holding ALEC Common Stock 1,972,875 10 Nov 2025 See footnote F2
holding ALEC Common Stock 652,500 10 Nov 2025 See footnote F3
holding ALEC Common Stock 652,500 10 Nov 2025 See footnote F4
holding ALEC Common Stock 652,500 10 Nov 2025 See footnote F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction ALEC Employee Stock Option (right to buy) Award $0 +522,500 $0.000000 522,500 10 Nov 2025 Common Stock 522,500 $1.31 Direct F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 The reported shares are represented by restricted stock units, or RSUs, which vest in 12 equal quarterly installments beginning on December 1, 2025.
F2 The reported securities are held directly by The Rosenthal Family Revocable Trust Dated November 4, 1994, as restated on June 9, 1999, for which the Reporting Person serves as trustee.
F3 The reported securities are held directly by the Adi Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.
F4 The reported securities are held directly by the Noam Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.
F5 The reported securities are held directly by the Shani Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.
F6 Shares subject to the option vest in 48 equal monthly installments beginning on December 10, 2025.