Ultragenyx CFO sells 4,653 company shares

Ultragenyx Pharmaceutical Inc. Chief Financial Officer Howard Horn reported an open-market sale of common stock.

Accepted by SEC EDGAR 06/01/2026 - 07:11 PM EDT Learn about SEC filing dates

Rhea-AI Filing Summary

Ultragenyx Pharmaceutical Inc. Chief Financial Officer Howard Horn reported an open-market sale of common stock. On June 1, 2026, he sold 4,653 shares at a price of $23.77 per share. After this transaction, he directly holds 105,689 shares, which include previously reported shares underlying RSUs that remain subject to vesting conditions.

Insider Trade Summary 10b5-1

Net Seller: 4,653 shares

Net Sell 1 txn

Insider Horn Howard

Role Chief Financial Officer

Sold 4,653 shs ($111K)

Type	Security	Shares	Price	Value
Sale	Common Stock	4,653	$23.77	$111K

Holdings After Transaction: Common Stock — 105,689 shares (Direct)

Footnotes (1)

1. F1. 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: 4,653 shares Sale price per share: $23.77 per share Shares held after transaction: 105,689 shares +2 more

5 metrics

Shares sold 4,653 shares Common Stock sold on June 1, 2026

Sale price per share $23.77 per share Open-market sale of Common Stock

Shares held after transaction 105,689 shares Direct holdings after June 1, 2026 sale

Number of sale transactions 1 sale transactionSummary sellCount

Net shares sold in period 4,653 shares transactionSummary netBuySellShares (net-sell)

Key Terms

open-market sale, Form 4, RSUs, vesting conditions

4 terms

open-market sale financial

"transaction_action is described as "open-market sale" of Common Stock"

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 regulatory

"reported in a Form 4 insider trading filing for Ultragenyx"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

RSUs financial

"shares of common stock underlying RSUs granted to the Reporting Person"

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.

vesting conditions financial

"RSUs granted to the Reporting Person, which are subject to certain vesting conditions"

Vesting conditions are the rules that determine when someone earning company stock or stock options actually gains the right to keep or sell them, typically based on staying with the company for a set time or meeting performance targets. Think of it like keys that unlock gradually — some unlock by calendar date, others only after agreed milestones. Investors care because vesting shapes management incentives, the timing of share sales, and the number of shares that can enter the market, which can affect a company's valuation and ownership mix.

FAQ

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

What insider transaction did Ultragenyx Pharmaceutical (RARE) disclose for Howard Horn?

Ultragenyx disclosed that CFO Howard Horn executed an open-market sale of common stock. He sold 4,653 shares on June 1, 2026, at a price of $23.77 per share, as reported in a Form 4 insider trading filing.

How many Ultragenyx (RARE) shares does CFO Howard Horn hold after the reported sale?

After the reported transaction, CFO Howard Horn directly holds 105,689 Ultragenyx common shares. This figure includes previously reported shares underlying RSUs that are subject to vesting conditions, according to the Form 4 filing’s footnote disclosure.

Was the Ultragenyx (RARE) CFO’s transaction a purchase or a sale of shares?

The transaction was a sale of Ultragenyx common stock by CFO Howard Horn. The Form 4 lists a transaction code “S,” indicating an open-market or private sale of 4,653 shares at $23.77 per share on June 1, 2026.

What does the Form 4 footnote say about Ultragenyx (RARE) RSUs held by the CFO?

The footnote explains that Horn’s reported holdings include shares underlying previously granted RSUs. These restricted stock units are subject to vesting conditions, meaning some of the reported 105,689 shares reflect unvested equity awards rather than fully vested, freely tradable stock.

How many insider sales are summarized in this Ultragenyx (RARE) Form 4 filing?

The Form 4 filing summarizes a single sale transaction in Ultragenyx common stock. The transactionSummary section shows one sale, covering 4,653 shares, with net buy-sell activity described as net-sell for this reporting period.

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

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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^*

Horn Howard

(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)
	Chief Financial Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/01/2026

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	06/01/2026		S		4,653	D	$23.77	105,689(1)	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. 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	06/01/2026
	** 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)