Ultragenyx Board Member's Stock Sale Signals Potential Shift in Biotech Sector

Rhea-AI Filing Summary

Form 4 filing reveals insider trading activity at Ultragenyx Pharmaceutical (RARE) by Director Corazon (Corsee) D. Sanders. On June 20, 2025, Sanders executed a significant sale of company shares:

• Disposed of 2,405 shares at a price of $37.39 per share
• Transaction value: approximately $89,873
• Retained ownership: 15,344 shares held directly

This insider sale represents a notable reduction in Sanders' direct holdings in Ultragenyx. The transaction was executed as a standard sale (transaction code 'S') and was reported within the required SEC filing deadline. No derivative securities transactions were reported in this filing.

Positive

• None.

Negative

• Director Corsee Sanders sold 2,405 shares at $37.39 per share (approximately $89,900 total value), retaining 15,344 shares

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^*

Sanders Corazon (Corsee) D.

(Last) (First) (Middle)

C/O ULTRAGENYX PHARMACEUTICAL INC.

60 LEVERONI COURT

(Street)

NOVATO CA 94949

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Ultragenyx Pharmaceutical Inc. [ RARE ]

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)
06/20/2025

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	06/20/2025		S		2,405	D	$37.39	15,344	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:

	/s/ Karah Parschauer, attorney-in-fact	06/23/2025
	** 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

How many shares of RARE stock did Director Sanders sell on June 20, 2025?

Director Corazon (Corsee) D. Sanders sold 2,405 shares of Ultragenyx Pharmaceutical Inc. (RARE) common stock on June 20, 2025.

What was the selling price of RARE shares in Director Sanders' transaction?

The shares were sold at a price of $37.39 per share.

How many RARE shares does Director Sanders own after the June 2025 sale?

Following the reported transaction, Director Sanders directly owns 15,344 shares of Ultragenyx Pharmaceutical Inc. (RARE) common stock.

What type of ownership does Director Sanders have in RARE stock?

Director Sanders has direct ownership (D) of the RARE shares, with no reported indirect ownership positions disclosed in the Form 4 filing.

When was the Form 4 for RARE insider trading filed with the SEC?

The Form 4 was filed with the SEC on June 28, 2025, reporting a transaction that occurred on June 20, 2025. The form was signed by Karah Parschauer as attorney-in-fact on June 23, 2025.