Alector, Inc. — Director's Dealing 2020

May 19, 2020

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Alector, Inc. (ALEC)
CIK: 0001653087
Period of Report: 2020-05-15

Reporting Person: Paul Robert (Chief Medical Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2020-05-15	Common Stock	S	1900	$26.15	Disposed	241819	Direct
2020-05-15	Common Stock	S	5996	$27.00	Disposed	235823	Direct
2020-05-15	Common Stock	S	2104	$27.78	Disposed	233719	Direct

Footnotes

F1: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $25.57 to $26.53 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

F3: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $26.60 to $27.59 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

F4: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $27.61 to $27.99 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.