[Form 4] Annexon, Inc. Insider Trading Activity

Rhea-AI Filing Summary

William H. Carson, a director of Annexon, Inc. (ANNX), purchased 4,115 shares of the company’s common stock on 09/30/2025 at a weighted average price of $3.05 per share under a Rule 10b5-1 trading plan adopted on March 17, 2025. After the reported purchase, the filing shows the reporting person beneficially owned 42,060 shares. The filing states the trades executed at prices ranging from $3.035 to $3.08, and the reporting person offers to provide details of the per-trade quantities on request. The transaction was reported on a Form 4 as required for Section 16 reporting.

Positive

• Director purchase: 4,115 shares acquired, signaling insider buying
• Pre-established plan: Trades executed under a Rule 10b5-1 plan adopted March 17, 2025
• Transparent pricing: Weighted average price disclosed as $3.05 with execution range $3.035–$3.08
• Post-transaction ownership: Reporting person beneficially owns 42,060 shares

Negative

• None.

Insights

Corporate Governance Analyst

Director purchased 4,115 ANNX shares via a 10b5-1 plan.

The director-level purchase of 4,115 shares at a weighted average price of $3.05 is a concrete insider transaction disclosed on Form 4 and executed under a pre-established Rule 10b5-1 plan adopted on March 17, 2025. Because the filing shows the trades occurred across a $3.035–$3.08 price range, the reported $3.05 reflects a weighted average of multiple executions.

This is material information for shareholders because Form 4 disclosures reveal executive trading activity and current beneficial ownership, which the form records as 42,060 shares following the purchase. Transaction date: 09/30/2025.

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).

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)
09/30/2025

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	09/30/2025		P(1)		4,115	A	$3.05(2)	42,060	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 March 17, 2025.

2. This transaction was executed in multiple trades in prices ranging from $3.035 o $3.08, inclusive. The price reported in Column 4 above reflects the weighted average purchase price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares purchased at each respective price within the range set forth in this footnote.

	/s/ Jennifer Lew, Attorney-in-Fact	10/02/2025
	** 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 did Annexon director William H. Carson purchase (ANNX)?

The director purchased 4,115 shares of Annexon common stock.

At what price were the ANNX shares bought?

The weighted average purchase price was $3.05; individual trades ranged from $3.035 to $3.08.

When was the transaction executed?

The reported transaction date is 09/30/2025.

Was the purchase part of a trading plan?

Yes. The trades were effected pursuant to a Rule 10b5-1 trading plan adopted on March 17, 2025.

How many ANNX shares does the reporting person own after the purchase?

The filing shows the reporting person beneficially owned 42,060 shares following the transaction.