What SEC filings does Ultragenyx Pharmaceutical Inc. submit to the SEC?

Ultragenyx Pharmaceutical Inc. (RARE) submits several types of SEC filings including Form 4 (insider transactions), Form 144 (proposed insider sales), 8-K reports (material events such as earnings releases, acquisitions, leadership changes), and periodic reports — the 10-Q (quarterly) and 10-K (annual). All filings are publicly available through SEC EDGAR.

What does a Form 4 filing tell me about RARE?

A Form 4 for RARE discloses a transaction by a company insider — typically a director, officer, or 10%+ shareholder. It shows the source-reported date, number of shares, price, and updated ownership. These facts do not establish motive or predict future returns.

How do I interpret an 8-K filing from Ultragenyx Pharmaceutical Inc.?

An 8-K signals a material event requiring prompt disclosure. Common triggers include earnings pre-announcements, acquisitions, leadership appointments or departures, credit changes, or regulatory actions. Read the item codes inside the filing to understand exactly what was disclosed before drawing conclusions.

What is the difference between a 10-K and 10-Q for RARE?

The 10-K is Ultragenyx Pharmaceutical Inc.'s annual report with fully audited financial statements, comprehensive MD&A, and complete risk factor disclosures — filed 60–90 days after fiscal year-end. The 10-Q is a lighter quarterly report with unaudited financials filed for the first three quarters. Together they provide a continuous financial picture of the company.

Where can I see all RARE SEC filings directly on EDGAR?

You can view all historical Ultragenyx Pharmaceutical Inc. filings on the SEC EDGAR company page for RARE. Each filing card on this page links directly to the original SEC document.

How often does Ultragenyx Pharmaceutical Inc. file with the SEC?

Ultragenyx Pharmaceutical Inc. files one 10-K per year and up to three 10-Qs per year. Form 4 insider transactions must be reported within two business days of each trade, so the frequency depends on how often insiders are buying or selling RARE shares. 8-K filings occur whenever a material event happens — which can be several times per quarter for an active company.

RARE SEC Filing News — Ultragenyx Pharmaceutical Inc.

Latest SEC filings for Ultragenyx Pharmaceutical Inc. (RARE) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-10-14.

Ultragenyx Pharmaceutical Inc., a biopharmaceutical company, focuses on the identification, acquisition, development, and commercialization of novel products for the treatment of rare and ultra-rare genetic diseases in North America, Latin America, Europe, the Middle East, Africa, and the Asia-Pacific. Its biologic products include Crysvita (burosumab), an antibody targeting fibroblast growth factor 23 for the treatment of X-linked hypophosphatemia, as well as tumor-induced osteomalacia; Mepsevi…

Sector: Healthcare Industry: Biotechnology Market Cap: $1.4B CIK: 1515673

Total Filings

Bullish Classifications

Bearish Classifications

Insider Transactions

Material Events (8-K)

Periodic Reports

Rule-based classifications for RARE currently lean bearish. Of the 20 filing records displayed, 7 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.

RARE Filing Activity Snapshot 2026-06-15 — 2026-10-14

Insider Transactions (Form 4)

0 buys vs 7 sells

Net insider selling in this period — insiders sell for many reasons beyond conviction.

Largest Form 144 Filing

$155.6K

Horn Howard (Chief Financial Officer) · 2026-07-06

4,698 shares · Form 4

Form 144 Notices

Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.

Insider Transactions 7 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 7 filings in this group are Form 4s for Ultragenyx Pharmaceutical Inc.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 7 insider filings shown, the breakdown is 7 open-market sale. 7 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Open-market sale ×7: The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Form 4 Open-market sale Insider Selling 2026-09-15

RARE insider Huizenga Theodore Alan (SVP, Chief Accounting Officer) sold 1,283 shares (~$17.4K)

Huizenga Theodore Alan, listed as SVP, Chief Accounting Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 1,283 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	1,283	$13.57	$17.4K

Filing: Form 4 (Insider Transaction) Insider: Huizenga Theodore Alan (SVP, Chief Accounting Officer) Shares: 1,283 Est. Value: $17.4K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-09-08

RARE insider Huizenga Theodore Alan (SVP, Chief Accounting Officer) sold 161 shares (~$2.3K)

Huizenga Theodore Alan, listed as SVP, Chief Accounting Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 161 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	161	$13.99	$2.3K

Filing: Form 4 (Insider Transaction) Insider: Huizenga Theodore Alan (SVP, Chief Accounting Officer) Shares: 161 Est. Value: $2.3K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-08-04

RARE insider Parschauer Karah Herdman (EVP and Chief Legal Officer) sold 1,900 shares (~$47.3K)

Parschauer Karah Herdman, listed as EVP and Chief Legal Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 1,900 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	1,900	$24.92	$47.3K

Filing: Form 4 (Insider Transaction) Insider: Parschauer Karah Herdman (EVP and Chief Legal Officer) Shares: 1,900 Est. Value: $47.3K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-08-04

RARE insider Horn Howard (Chief Financial Officer) sold 4,696 shares (~$117.0K)

Horn Howard, listed as Chief Financial Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 4,696 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	4,696	$24.92	$117.0K

Filing: Form 4 (Insider Transaction) Insider: Horn Howard (Chief Financial Officer) Shares: 4,696 Est. Value: $117.0K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-07-06

RARE insider Horn Howard (Chief Financial Officer) sold 4,698 shares (~$155.6K)

Horn Howard, listed as Chief Financial Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 4,698 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	4,698	$33.13	$155.6K

Filing: Form 4 (Insider Transaction) Insider: Horn Howard (Chief Financial Officer) Shares: 4,698 Est. Value: $155.6K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-06-15

RARE insider Sanders Corazon (Corsee) D. (Director) sold 2,000 shares (~$50.1K)

Sanders Corazon (Corsee) D., listed as Director at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 2,000 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	2,000	$25.05	$50.1K

Filing: Form 4 (Insider Transaction) Insider: Sanders Corazon (Corsee) D. (Director) Shares: 2,000 Est. Value: $50.1K

View on SEC EDGAR → Open Filing Document →

Form 4 Open-market sale Insider Selling 2026-06-15

RARE insider Parschauer Karah Herdman (EVP and Chief Legal Officer) sold 1,899 shares (~$46.8K)

Parschauer Karah Herdman, listed as EVP and Chief Legal Officer at Ultragenyx Pharmaceutical Inc., reported an open-market sale of 1,899 RARE shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`S`	Open-market sale	1,899	$24.62	$46.8K

Filing: Form 4 (Insider Transaction) Insider: Parschauer Karah Herdman (EVP and Chief Legal Officer) Shares: 1,899 Est. Value: $46.8K

View on SEC EDGAR → Open Filing Document →

Proposed Insider Sales 5 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. Ultragenyx Pharmaceutical Inc. has 5 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-09-15

RARE Form 144 filed for proposed insider sale by THEODORE HUIZENGA (1,283 shares) ~$17.5K

THEODORE HUIZENGA filed a Form 144 with the SEC indicating intent to sell RARE (Ultragenyx Pharmaceutical Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: THEODORE HUIZENGA Shares: 1,283 Est. Value: $17.5K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-08-03

RARE Form 144 filed for proposed insider sale by HOWARD HORN (4,696 shares) ~$117.0K

HOWARD HORN filed a Form 144 with the SEC indicating intent to sell RARE (Ultragenyx Pharmaceutical Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: HOWARD HORN Shares: 4,696 Est. Value: $117.0K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-07-01

RARE Form 144 filed for proposed insider sale by HOWARD HORN (4,698 shares) ~$155.6K

Filing: Form 144 (Proposed Sale Notice) Insider: HOWARD HORN Shares: 4,698 Est. Value: $155.6K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-06-15

RARE Form 144 filed for proposed insider sale by KARAH PARSCHAUER (3,799 shares) ~$92.5K

KARAH PARSCHAUER filed a Form 144 with the SEC indicating intent to sell RARE (Ultragenyx Pharmaceutical Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: KARAH PARSCHAUER Shares: 3,799 Est. Value: $92.5K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-06-15

RARE Form 144 filed for proposed insider sale by CORAZON D. SANDERS (2,000 shares) ~$50.1K

CORAZON D. SANDERS filed a Form 144 with the SEC indicating intent to sell RARE (Ultragenyx Pharmaceutical Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: CORAZON D. SANDERS Shares: 2,000 Est. Value: $50.1K

View on SEC EDGAR → Open Filing Document →

Material Events 7 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 7 in this period for Ultragenyx Pharmaceutical Inc. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K Material Company Update 2026-10-14