<div id="readability-page-1"><div><p><span>Horn Howard, Chief Financial Officer of Ultragenyx Pharmaceutical Inc [RARE], filed a Form 144 on December 10, 2025 with the Securities and Exchange Commission proposing to sell restricted securities:</span></p><div><table><tbody><tr><td><span>Approximate Date Of Sale</span></td><td><span>12/10/25</span></td></tr><tr><td><span>Shares</span></td><td><span>3,081</span></td></tr><tr><td><span>Broker</span></td><td><span>Morgan Stanley Smith Barney LLC</span></td></tr></tbody></table></div><ul><li><span>*</span></li><li><span>Executed pursuant to a prearranged trading plan (10b5-1).</span></li></ul><p><span>Prior to the sale of restricted stock, owners must file a Form 144 with the SEC.  Upon submission of the filing to the SEC the owner is permitted to sell the shares, or any fraction thereof, within 90 days.</span></p><p><span>For a free trial, or to learn more about our insider trading analysis and data services, please visit http://www.washingtonservice.com or contact us at (301) 913-5100 or send an email to info@washingtonservice.com.</span></p><p><span>Founded in 1970, The Washington Service provides securities professionals with financial, economic and public policy research and data.</span></p><span> </span></div></div>

RARE

<p>CFO Horn Howard of Ultragenyx Pharmaceutical Inc filed a Form 144 with the SEC to sell 3,081 shares on December 10, 2025, through Morgan Stanley Smith Barney LLC, under a prearranged trading plan (10b5-1).</p>

CFO Horn Files To Sell 3,081 Of Ultragenyx Pharmaceutical Inc [RARE]