Ultragenyx (NASDAQ: RARE) CMO sells shares to cover RSU taxes

Rhea-AI Filing Summary

Ultragenyx Pharmaceutical Inc. executive Eric Crombez, EVP and Chief Medical Officer, sold 344 shares of common stock at $24.96 per share on May 5, 2026. According to the footnotes, these shares were sold to pay required tax withholdings related to the vesting of restricted stock units (RSUs). After this tax-related sale, Crombez directly holds 111,189 shares of Ultragenyx common stock.

Insider Trade Summary

Net Seller: 344 shares ($8,586)

Net Sell 1 txn

Insider Crombez Eric

Role EVP and Chief Medical Officer

Sold 344 shs ($9K)

Type	Security	Shares	Price	Value
Sale	Common Stock	344	$24.96	$9K

Holdings After Transaction: Common Stock — 111,189 shares (Direct, null)

Footnotes (1)

1. Represents shares sold to pay required tax withholdings due to the vesting of RSUs. Includes 558 shares acquired under the Company's Amended and Restated Employee Stock Purchase Plan on April 30, 2026 Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.

Key Figures

Shares sold: 344 shares Sale price: $24.96 per share Post-transaction holdings: 111,189 shares +1 more

4 metrics

Shares sold 344 shares Open-market sale on May 5, 2026

Sale price $24.96 per share Price for 344 shares sold

Post-transaction holdings 111,189 shares Common stock held directly after sale

ESPP acquisition 558 shares Acquired under Employee Stock Purchase Plan on April 30, 2026

Key Terms

RSUs, Employee Stock Purchase Plan, tax withholdings, open-market sale

4 terms

RSUs financial

"due to the vesting of RSUs."

RSUs, or restricted stock units, are a form of company shares given to employees as part of their compensation. They are typically awarded with certain restrictions, such as a waiting period before they can be fully owned or sold, similar to earning a gift that becomes fully yours over time. For investors, RSUs can impact a company's stock offerings and reflect how much the company relies on stock-based incentives to attract and retain talent.

Employee Stock Purchase Plan financial

"acquired under the Company's Amended and Restated Employee Stock Purchase Plan"

An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.

tax withholdings financial

"shares sold to pay required tax withholdings due to the vesting of RSUs"

open-market sale financial

"transaction_action": "open-market sale""

An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.

Form 4 Insider Transactions: What Each Field Means →

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^*

Crombez Eric

(Last) (First) (Middle)

C/O ULTRAGENYX PHARMACEUTICAL INC.

60 LEVERONI COURT

(Street)

NOVATO CALIFORNIA 94949

(City) (State) (Zip)

UNITED STATES

(Country)

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

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP and Chief Medical Officer

2a. Foreign Trading Symbol

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

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	05/05/2026		S		344(1)	D	$24.96	111,189(2)(3)	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. Represents shares sold to pay required tax withholdings due to the vesting of RSUs.

2. Includes 558 shares acquired under the Company's Amended and Restated Employee Stock Purchase Plan on April 30, 2026

3. Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.

	/s/ Karah Parschauer, attorney-in-fact	05/06/2026
	** 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)

FAQ

What did Ultragenyx (RARE) executive Eric Crombez report in this Form 4 filing?

Eric Crombez reported selling 344 Ultragenyx common shares. The shares were sold at $24.96 each to cover tax withholdings from vesting RSUs, and he continues to hold 111,189 shares directly after the transaction.

Was the Ultragenyx (RARE) insider sale by Eric Crombez a discretionary trade?

The filing states the 344 Ultragenyx shares sold by Eric Crombez were used to pay required tax withholdings from RSU vesting. This indicates a tax-related, mechanical sale rather than a purely discretionary open-market liquidation of his equity position.

How many Ultragenyx (RARE) shares does Eric Crombez hold after this Form 4 transaction?

After selling 344 shares to cover RSU-related tax obligations, Eric Crombez directly holds 111,189 Ultragenyx common shares. This post-transaction balance, disclosed in the filing, shows he retains a substantial equity stake in the company following the tax sale.

At what price were the Ultragenyx (RARE) shares sold in Eric Crombez’s Form 4?

The 344 Ultragenyx shares were sold at an average price of $24.96 per share. The filing describes this as an open-market sale, with footnotes clarifying the proceeds were used to satisfy required tax withholdings from RSU vesting.

Do RSUs and the Employee Stock Purchase Plan affect Eric Crombez’s Ultragenyx (RARE) holdings?

Yes. Footnotes note Crombez’s holdings include shares underlying RSUs subject to vesting conditions and 558 shares acquired under Ultragenyx’s Amended and Restated Employee Stock Purchase Plan on April 30, 2026, in addition to his directly held common stock.