Ultragenyx (RARE) CFO sells stock under 10b5-1 plan, keeps 96,295 shares

Rhea-AI Filing Summary

Ultragenyx Pharmaceutical Inc. reports that Chief Financial Officer Howard Horn sold 4,696 shares of common stock on August 3, 2026 at $24.92 per share in an open-market or private transaction under a Rule 10b5-1 trading plan, and now directly holds 96,295 shares, including shares underlying RSUs that remain subject to vesting conditions.

Insider Trade Summary 10b5-1

Net Seller: 4,696 shares

Net Sell 1 txn

Insider Horn Howard

Role Chief Financial Officer

Sold 4,696 shs ($117K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1	4,696	$24.92	$117K

Holdings After Transaction: Common Stock — 96,295 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: 4,696 shares Sale price per share: $24.92 Shares held after transaction: 96,295 shares +1 more

4 metrics

Shares sold 4,696 shares Common stock sale reported for August 3, 2026

Sale price per share $24.92 Per-share price for the 4,696-share sale

Shares held after transaction 96,295 shares Direct common stock holdings after the sale, including RSU-based shares

Net shares sold in filing 4,696 shares Net insider share change; transactionSummary net-sell

Key Terms

RSUs, vesting conditions, open market or private transaction

3 terms

RSUs financial

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

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.

open market or private transaction financial

"transaction code description: Sale in open market or private transaction"

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

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Form 4 Insider Transactions: What Each Field Means →

Available on EDGAR 08/04/2026 - 03:14 PM Accepted by SEC EDGAR 08/04/2026 - 03:13 PM Learn about SEC filing dates

FAQ

What insider transaction did Ultragenyx (RARE) report for CFO Howard Horn?

Ultragenyx reported that CFO Howard Horn sold 4,696 shares of common stock on August 3, 2026 at $24.92 per share in an open-market or private transaction executed under a Rule 10b5-1 trading plan.

How many Ultragenyx (RARE) shares did CFO Howard Horn sell and at what price?

CFO Howard Horn sold 4,696 shares of Ultragenyx common stock at a price of $24.92 per share. The transaction is characterized as a sale in an open market or private transaction according to the Form 4 disclosure.

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

After the reported sale, CFO Howard Horn directly holds 96,295 shares of Ultragenyx common stock. This total includes shares underlying previously reported RSUs that are still subject to certain vesting conditions, as noted in the footnote.

Was the Ultragenyx (RARE) CFO stock sale made under a Rule 10b5-1 plan?

Yes. The Form 4 indicates that the transactions were made under a Rule 10b5-1 trading plan, as shown by the plan affirmation checkbox. This means the trades were pre-arranged according to predetermined instructions.

Do Howard Horn’s reported Ultragenyx (RARE) holdings include RSUs?

Yes. A footnote explains that the reported 96,295-share position includes common stock underlying previously reported RSUs granted to him, which remain subject to vesting conditions rather than being fully vested shares.

Is the Ultragenyx (RARE) CFO’s ownership on the Form 4 direct or indirect?

The reported holdings are classified as direct ownership. The Form 4 lists the ownership code as "D", indicating direct ownership by CFO Howard Horn rather than through a separate entity or indirect arrangement.

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)
08/03/2026

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	08/03/2026		S		4,696	D	$24.92	96,295(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	08/04/2026
	** 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)