Theodore Alan Huizenga - 29 Dec 2025 Form 4 Insider Report for Ultragenyx Pharmaceutical Inc. (RARE)

Role: SVP, Chief Accounting Officer
Signature: /s/ Karah Parschauer, attorney-in-fact
Issuer symbol: RARE
Transactions as of: 29 Dec 2025
Net transactions value: -$2,922
Form type: 4
Filing time: 30 Dec 2025, 13:49:27 UTC
Previous filing: 19 Sep 2025
Next filing: 03 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Huizenga Theodore Alan	SVP, Chief Accounting Officer	C/O ULTRAGENYX PHARMACEUTICAL INC., 60 LEVERONI COURT, NOVATO	/s/ Karah Parschauer, attorney-in-fact	30 Dec 2025	0001603347

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	RARE	Common Stock	Sale	$2,922	-85	-0.17%	$34.38	50,450	29 Dec 2025	Direct	F1, F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents shares sold to pay required tax withholdings due to the vesting of RSUs.
F2	Includes 293 shares acquired under the Company's A&R 2014 Employee Stock Purchase Plan on October 31, 2025.
F3	Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.