Annexon director-linked fund buys 613K shares

Annexon, Inc. director Muneer A. Satter, through an affiliated investment entity, reported a large open-market purchase of the company’s common stock.

Rhea-AI Filing Summary

Annexon, Inc. director Muneer A. Satter, through an affiliated investment entity, reported a large open-market purchase of the company’s common stock. On May 28, 2026, Alerce Medical Technology Partners, L.P. bought 613,497 shares at a price of $5.41 per share, with Satter having sole voting and dispositive power over these shares.

After this transaction, entities associated with Satter are shown as holding 10,342,134 shares in total, including 240,000 shares in the Muneer A. Satter Revocable Trust and additional shares in various trusts and partnerships. Satter disclaims beneficial ownership of many of these indirect holdings except to the extent of his pecuniary interest.

Insider Trade Summary

Net Buyer: 613,497 shares

Net Buy 1 txn

Insider Satter Muneer A

Role Director

Bought 613,497 shs ($3.32M)

Type	Security	Shares	Price	Value
Purchase	Common Stock	613,497	$5.41	$3.32M

Holdings After Transaction: Common Stock — 10,342,134 shares (Indirect, See footnote)

Footnotes (2)

1. F1. All shares were purchased by Alerce Medical Technology Partners, L.P. ("Alerce Medical"). The Reporting Person has sole voting and dispositive power over the shares held by Alerce Medical. The Reporting Person disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein.
2. F2. As of May 28, 2026, includes (a) 240,000 shares that are held by the Muneer A. Satter Revocable Trust for which the Reporting Person serves as trustee and, in such capacity, has sole voting and dispositive power over all such shares, (b) 567,240 shares that are held by various other trusts and entities for which the Reporting Person serves as trustee, investment advisor or manager, as applicable, and, in each such capacity, has sole voting and dispositive power over all such shares, (c) 1,147,738 shares that are held by Satter Medical Technology Partners, L.P. for which the Reporting Person has sole voting and dispositive power over all such shares and (d) 8,387,156 shares that are held by Alerce Medical for which the Reporting Person has sole voting and dispositive power over all such shares. The Reporting Person disclaims beneficial ownership of all shares included under (b), (c) and (d) of this footnote, except to the extent of his pecuniary interest therein.

Key Figures

Shares purchased: 613,497 shares Purchase price: $5.41 per share Indirect holdings after transaction: 10,342,134 shares +4 more

7 metrics

Shares purchased 613,497 shares Open-market common stock purchase on May 28, 2026

Purchase price $5.41 per share Price paid for Annexon common stock in the reported trade

Indirect holdings after transaction 10,342,134 shares Total Annexon shares held by entities associated with Satter

Revocable trust holdings 240,000 shares Shares held by the Muneer A. Satter Revocable Trust as of May 28, 2026

Other trusts and entities 567,240 shares Shares held by various other trusts and entities as of May 28, 2026

Satter Medical Technology Partners, L.P. 1,147,738 shares Annexon shares held by this partnership as of May 28, 2026

Alerce Medical Technology Partners, L.P. 8,387,156 shares Annexon shares held by Alerce Medical as of May 28, 2026

Key Terms

open-market purchase, voting and dispositive power, disclaims beneficial ownership, pecuniary interest, +1 more

5 terms

open-market purchase financial

"The transaction is described as an open-market purchase of common stock."

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

voting and dispositive power financial

"The Reporting Person has sole voting and dispositive power over the shares held by Alerce Medical."

disclaims beneficial ownership financial

"The Reporting Person disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein."

pecuniary interest financial

"He disclaims beneficial ownership of certain shares except to the extent of his pecuniary interest therein."

Revocable Trust financial

"Includes 240,000 shares that are held by the Muneer A. Satter Revocable Trust."

A revocable trust is a legal arrangement where the person who creates it keeps control and can change or cancel the trust at any time, while naming who will manage and receive the assets later. Think of it like a flexible folder for your investments and property that can be relabeled or reworked as circumstances change; it matters to investors because it determines how ownership is recorded, how easily assets transfer on incapacity or death, and whether holdings bypass public probate proceedings.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did Annexon (ANNX) disclose for Muneer A. Satter?

Annexon disclosed that an entity associated with director Muneer A. Satter bought 613,497 common shares. The purchase was made in an open-market transaction, with Satter having sole voting and dispositive power over the acquired shares.

How many Annexon (ANNX) shares were purchased and at what price?

The filing reports a purchase of 613,497 Annexon common shares at $5.41 per share. This was an open-market transaction, indicating a sizeable addition to the indirect holdings associated with director Muneer A. Satter.

Who actually holds the newly purchased Annexon (ANNX) shares?

All newly purchased shares are held by Alerce Medical Technology Partners, L.P. Director Muneer A. Satter has sole voting and dispositive power over Alerce Medical’s holdings, according to the footnote in the insider filing.

What are the total Annexon (ANNX) indirect holdings associated with Muneer A. Satter?

After the reported transaction, entities associated with Muneer A. Satter hold 10,342,134 Annexon shares. This total includes shares in a revocable trust, other trusts and entities, Satter Medical Technology Partners, L.P., and Alerce Medical Technology Partners, L.P.

Does Muneer A. Satter claim full beneficial ownership of all Annexon (ANNX) shares reported?

No. The filing states Satter disclaims beneficial ownership of shares held by certain trusts and partnerships, including Alerce Medical, except to the extent of his pecuniary interest in those entities’ Annexon holdings.

What trusts and entities are mentioned in the Annexon (ANNX) insider filing?

The filing mentions the Muneer A. Satter Revocable Trust, various other trusts and entities where Satter serves as trustee or advisor, Satter Medical Technology Partners, L.P., and Alerce Medical Technology Partners, L.P., all holding Annexon shares.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/29/2026 - 05:21 PM EDT Learn about SEC filing dates

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^*

Satter Muneer A

(Last) (First) (Middle)

C/O ANNEXON, INC.

1400 SIERRA POINT PKWY, BLDG C, STE 200

(Street)

BRISBANE CALIFORNIA 94005

(City) (State) (Zip)

UNITED STATES

(Country)

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)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/28/2026

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

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

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

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	05/28/2026		P		613,497(1)	A	$5.41	10,342,134	I	See footnote(2)

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. All shares were purchased by Alerce Medical Technology Partners, L.P. ("Alerce Medical"). The Reporting Person has sole voting and dispositive power over the shares held by Alerce Medical. The Reporting Person disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein.

2. As of May 28, 2026, includes (a) 240,000 shares that are held by the Muneer A. Satter Revocable Trust for which the Reporting Person serves as trustee and, in such capacity, has sole voting and dispositive power over all such shares, (b) 567,240 shares that are held by various other trusts and entities for which the Reporting Person serves as trustee, investment advisor or manager, as applicable, and, in each such capacity, has sole voting and dispositive power over all such shares, (c) 1,147,738 shares that are held by Satter Medical Technology Partners, L.P. for which the Reporting Person has sole voting and dispositive power over all such shares and (d) 8,387,156 shares that are held by Alerce Medical for which the Reporting Person has sole voting and dispositive power over all such shares. The Reporting Person disclaims beneficial ownership of all shares included under (b), (c) and (d) of this footnote, except to the extent of his pecuniary interest therein.

	/s/ Muneer A. Satter	05/29/2026
	** 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.
* Form 4: SEC 1474 (03-26)