[Form 4] Annexon, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Annexon, Inc. director William H. Carson reported an open-market purchase of 8,000 shares of Common Stock at $5.67 per share. Following this transaction, he directly owns 62,405 shares. The filing notes the trade was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 8, 2025.

Insider Trade Summary 10b5-1

Net Buyer: 8,000 shares ($45,360)

Net Buy 1 txn

Insider Carson William H.

Role Director

Bought 8,000 shs ($45K)

Type	Security	Shares	Price	Value
Purchase	Common Stock	8,000	$5.67	$45K

Holdings After Transaction: Common Stock — 62,405 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

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).

X

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^*

Carson William H.

(Last) (First) (Middle)

C/O ANNEXON, INC.

1400 SIERRA POINT PKWY, BLDG C, STE 200

(Street)

BRISBANE CA 94005

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Annexon, Inc. [ ANNX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

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	03/10/2026		P(1)		8,000	A	$5.67	62,405	D

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 transactions reported herein were effected pursuant to the Reporting Person's Rule 10b5-1 trading plan, adopted December 8, 2025.

	/s/ Jennifer Lew, Attorney-in-Fact	03/12/2026
	** 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 insider transaction did Annexon (ANNX) director William H. Carson report?

Director William H. Carson reported buying 8,000 shares of Annexon Common Stock. The purchase was an open-market transaction at $5.67 per share, as disclosed in a Form 4 insider trading report.

At what price did the Annexon (ANNX) director purchase shares?

The Annexon director purchased shares at $5.67 each. The Form 4 filing specifies that 8,000 shares of Common Stock were acquired in an open-market transaction at this price per share.

How many Annexon (ANNX) shares does William H. Carson hold after the transaction?

After the purchase, William H. Carson directly holds 62,405 Annexon shares. This total includes the newly acquired 8,000 shares reported in the Form 4 insider transaction filing.

Was the Annexon (ANNX) director’s share purchase under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effected under the reporting person’s Rule 10b5-1 trading plan, which was adopted on December 8, 2025, indicating the trades were pre-arranged.

What type of security did the Annexon (ANNX) insider buy in the Form 4?

The insider bought Annexon Common Stock. The Form 4 identifies the security title as Common Stock, with 8,000 shares acquired in an open-market purchase at $5.67 per share.

Is the Annexon (ANNX) insider transaction a purchase or sale?

The Annexon insider transaction is a purchase. The Form 4 uses transaction code “P” for an open-market purchase and classifies the direction as a buy of 8,000 Common Stock shares.