Theodore Alan Huizenga - 01 Mar 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: 01 Mar 2025
Net transactions value: -$46,762
Form type: 4
Filing time: 04 Mar 2025, 20:00:32 UTC
Previous filing: 11 Dec 2024
Next filing: 08 Sep 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	RARE	Common Stock	Award	$0	+9,392	+22%	$0.000000	51,232	01 Mar 2025	Direct	F1
transaction	RARE	Common Stock	Sale	$40,711	-967	-1.9%	$42.10	50,265	03 Mar 2025	Direct	F2, F3
transaction	RARE	Common Stock	Tax liability	$6,052	-141	-0.28%	$42.92	50,124	03 Mar 2025	Direct	F4, F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	RARE	Stock Option (Right to Buy)	Award	$0	+5,632		$0.000000	5,632	01 Mar 2025	Common Stock	5,632	$42.92	Direct	F6

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

Explanation of Responses:

Id	Content
F1	Award of Restricted Stock Units ("RSUs") under the Company's 2023 Incentive Plan. The RSUs shall vest with respect to 1/4th of the underlying shares on each anniversary of the grant date, such that the RSUs are fully vested on the fourth anniversary of the grant date
F2	Represents shares sold to pay required tax withholdings due to the vesting of RSUs.
F3	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $41.77 to $42.90 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.
F4	Represents shares surrendered to the Issuer by the Reporting Person to pay required tax withholdings due to the vesting of RSUs.
F5	Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.
F6	On the first anniversary of the grant date of the option (the "Option Anniversary Date"), 1/4th of the shares initially subject to the option shall vest; thereafter, 1/48th of the shares initially subject to the option shall vest on each month as measured from the Option Anniversary Date.