Arnon Rosenthal - Dec 3, 2025 Form 4 Insider Report for Alector, Inc. (ALEC)

Role
Chief Executive Officer, Director
Signature
/s/ Grace Wong-Sarad, by power of attorney
Stock symbol
ALEC
Transactions as of
Dec 3, 2025
Transactions value $
-$116,827
Form type
4
Date filed
12/3/2025, 09:06 PM
Previous filing
Nov 12, 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 2025-12-03 0001757770

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ALEC Common Stock Sale -$117K -104K -4.13% $1.12 2.42M Dec 3, 2025 Direct F1, F2
holding ALEC Common Stock 1.97M Dec 3, 2025 See footnote F3
holding ALEC Common Stock 653K Dec 3, 2025 See footnote F4
holding ALEC Common Stock 653K Dec 3, 2025 See footnote F5
holding ALEC Common Stock 653K Dec 3, 2025 See footnote F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 The reported shares were sold to satisfy the reporting person's tax obligations in connection with the vesting of restricted stock units, or RSUs.
F2 The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $1.095 to $1.14. Full information regarding the number of shares sold at each separate price can be furnished to the SEC staff, the issuer, or any security holder of the issuer upon request.
F3 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.
F4 The reported securities are held directly by the Adi Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.
F5 The reported securities are held directly by the Noam Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.
F6 The reported securities are held directly by the Shani Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.