Alector (ALEC) CEO awarded 116,246 RSUs, boosts direct share stake

Rhea-AI Filing Summary

Rosenthal Arnon reported acquisition or exercise transactions in this Form 4 filing.

Alector, Inc. chief executive officer Arnon Rosenthal reported an equity compensation grant of restricted stock units representing 116,246 shares of common stock on March 13, 2026. The RSUs were granted at no cash cost and will vest in two equal installments: one half on September 1, 2026 and one half on March 1, 2027.

Following the award, Rosenthal directly owns 2,454,422 common shares. He also reports additional indirect holdings through family trusts, including shares held by The Rosenthal Family Revocable Trust and by three 2007 trusts for family members.

Insights

Equity compensation analyst

CEO receives time-vested RSU grant, boosting direct equity stake.

Alector’s CEO Arnon Rosenthal was granted restricted stock units over 116,246 common shares with no purchase price. These RSUs vest in two equal tranches on September 1, 2026 and March 1, 2027, encouraging multi‑year retention and alignment.

After this grant, Rosenthal directly owns 2,454,422 common shares, plus substantial indirect holdings through the Rosenthal Family Revocable Trust and three 2007 family trusts where he serves as trustee. This filing reflects compensation, not open‑market buying or selling, and does not change cash balances or signal trading views.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Rosenthal Arnon

(Last) (First) (Middle)

C/O ALECTOR, INC.

131 OYSTER POINT BLVD., SUITE 600

(Street)

SOUTH SAN FRANCISCO CA 94080

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Alector, Inc. [ ALEC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/13/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/13/2026		A		116,246(1)	A	$0.00	2,454,422	D
Common Stock								1,972,875	I	See footnote(2)
Common Stock								652,500	I	See footnote(3)
Common Stock								652,500	I	See footnote(4)
Common Stock								652,500	I	See footnote(5)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The reported shares are represented by restricted stock units, or RSUs, one half (1/2) of the total shares shall vest on September 1, 2026 and one half (1/2th) of the total shares shall vest on March 1, 2027.

2. 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.

3. The reported securities are held directly by the Adi Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.

4. The reported securities are held directly by the Noam Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.

5. The reported securities are held directly by the Shani Rosenthal 2007 Trust dated March 27, 2007, for which the Reporting Person serves as trustee.

	/s/ Grace Wong-Sarad, by power of attorney	03/13/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What equity award did Alector (ALEC) CEO Arnon Rosenthal receive in this Form 4?

Arnon Rosenthal received restricted stock units over 116,246 Alector common shares. The award is a compensation grant at no cash cost, increasing his direct equity exposure rather than reflecting an open‑market share purchase.

How do the new RSUs for Alector (ALEC) CEO vest over time?

The RSUs vest in two equal installments. One half of the 116,246 units vests on September 1, 2026, and the remaining half vests on March 1, 2027, supporting multi‑year retention and performance alignment for the CEO.

How many Alector (ALEC) shares does the CEO directly hold after this transaction?

Following the RSU grant, Arnon Rosenthal directly holds 2,454,422 Alector common shares. This figure reflects his direct ownership only and excludes additional indirect holdings reported through various Rosenthal family trusts where he serves as trustee.

Were there any open‑market share purchases or sales in this Alector (ALEC) Form 4?

No open‑market purchases or sales were reported. The primary transaction is a Form 4 code A equity grant, meaning the CEO acquired restricted stock units as compensation rather than buying or selling shares in the public market.

What indirect Alector (ALEC) holdings does the CEO report through family trusts?

Indirect holdings are reported in trusts where Arnon Rosenthal is trustee. These include The Rosenthal Family Revocable Trust and three 2007 trusts for family members, each holding Alector common stock as disclosed in the Form 4 footnotes.

Does this Alector (ALEC) Form 4 indicate any remaining derivative positions for the CEO?

The derivative section of the filing is empty, indicating no options or other derivative securities are reported in this Form 4. The disclosure focuses on common stock, including the new RSU grant and existing direct and indirect share holdings.