BlackRock reports 17.10M shares (12.2%) of Arrowhead

Arrowhead Pharmaceuticals reports that BlackRock, Inc. beneficially owned 17,104,084 shares of Common Stock, representing 12.2% of the class as of 03/31/2026.

Rhea-AI Filing Summary

Arrowhead Pharmaceuticals reports that BlackRock, Inc. beneficially owned 17,104,084 shares of Common Stock, representing 12.2% of the class as of 03/31/2026. The filing states BlackRock has sole voting power for 16,769,679 shares and sole dispositive power for 17,104,084 shares. The filing is an amendment (No. 5) to a Schedule 13G/A and is signed by a BlackRock managing director on 04/24/2026.

Insights

Institutional Ownership Analyst

BlackRock holds a significant passive stake in Arrowhead at 12.2%.

BlackRock, reported as beneficial owner of 17,104,084 shares with sole voting power over 16,769,679 shares. The Schedule 13G/A format indicates passive investment intent under SEC rules, rather than an active control statement.

Watch subsequent filings for any change in ownership percentage or a shift to active status; timing shown in the cover information is 03/31/2026.

Regulatory Compliance Specialist

The amendment and exhibit references indicate record updates and subsidiary detail disclosure.

The filing references Exhibit 99 for Item 7 and Exhibit 24 for power of attorney, consistent with parent/subsidiary identification practices. The cover notes the disclosure aggregates certain BlackRock business units per SEC Release No. 34-39538.

Further disclosures in exhibits would identify any acquiring subsidiary; check future amendments or exhibits for that detail.

Key Figures

Beneficial ownership: 17,104,084 shares Percent of class: 12.2% Sole voting power: 16,769,679 shares +4 more

7 metrics

Beneficial ownership 17,104,084 shares Amount beneficially owned as reported

Percent of class 12.2% Percent of common stock as reported

Sole voting power 16,769,679 shares Sole power to vote or direct the vote

Sole dispositive power 17,104,084 shares Sole power to dispose or direct disposition

Filing type Schedule 13G/A (Amendment No. 5) Form classification stated on cover

Reporting date 03/31/2026 Date shown on the cover page

Signature date 04/24/2026 Date signed by Spencer Fleming, Managing Director

Key Terms

Schedule 13G/A, Beneficially owned, Sole dispositive power, SEC Release No. 34-39538

4 terms

Schedule 13G/A regulatory

"Amendment No. 5 ) ARROWHEAD PHARMACEUTICALS INC Common Stock"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

Beneficially owned financial

"Amount beneficially owned: 17104084"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

Sole dispositive power regulatory

"Sole power to dispose or to direct the disposition of: 17104084"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

SEC Release No. 34-39538 regulatory

"In accordance with SEC Release No. 34-39538 (January 12, 1998)"

FAQ

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

What stake does BlackRock report in ARWR (Arrowhead) in this Schedule 13G/A?

BlackRock reports beneficial ownership of 17,104,084 shares, representing 12.2% of Arrowhead's common stock as of 03/31/2026. The filing shows sole voting power for 16,769,679 shares and sole dispositive power for 17,104,084 shares.

Does this Schedule 13G/A indicate BlackRock seeks control of Arrowhead (ARWR)?

No; the Schedule 13G/A format and the filing language indicate a passive reporting status under SEC rules. It lists beneficial ownership and voting/dispositive power without asserting active control or a change to an acquisition intent.

What reporting dates and signature date appear in the BlackRock 13G/A for ARWR?

The cover shows a reporting date of 03/31/2026 and the amendment is signed by Spencer Fleming, Managing Director, on 04/24/2026. The filing is labeled as Amendment No. 5 to the Schedule 13G/A.

How does BlackRock aggregate holdings in this filing for Arrowhead (ARWR)?

The filing states holdings are aggregated for certain business units of BlackRock, Inc., per SEC Release No. 34-39538. It excludes securities held by other BlackRock business units that are disaggregated under that release.

What exhibits are referenced in the BlackRock Schedule 13G/A for ARWR?

The filing references Exhibit 24 (Power of Attorney) and Exhibit 99 (Item 7 information identifying the subsidiary when a parent holding company is involved). Exhibit details would provide subsidiary identification if applicable.

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

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Accepted by SEC EDGAR 04/24/2026 - 04:11 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 5)

ARROWHEAD PHARMACEUTICALS INC

(Name of Issuer)

Common Stock

(Title of Class of Securities)

04280A100

(CUSIP Number)

03/31/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 04280A100

1

Names of Reporting Persons

BlackRock, Inc.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 16,769,679.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 17,104,084.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

17,104,084.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

12.2 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

Item 1.
(a)	Name of issuer: ARROWHEAD PHARMACEUTICALS INC
(b)	Address of issuer's principal executive offices: 177 E COLORADO BLVD, SUITE 700 PASADENA CA 91105
Item 2.
(a)	Name of person filing: BlackRock, Inc. In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by certain business units (collectively, the "Reporting Business Units") of BlackRock, Inc. and its subsidiaries and affiliates. It does not include securities, if any, beneficially owned by other business units whose beneficial ownership of securities are disaggregated from that of the Reporting Business Units in accordance with such release.
(b)	Address or principal business office or, if none, residence: BlackRock, Inc., 50 Hudson Yards New York, NY 10001
(c)	Citizenship: See Item 4 of Cover Page
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 04280A100
Item 4.	Ownership
(a)	Amount beneficially owned: 17104084
(b)	Percent of class: 12.2 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 16769679
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 17104084
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. Various persons have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of the common stock of ARROWHEAD PHARMACEUTICALS INC. No one person's interest in the common stock of ARROWHEAD PHARMACEUTICALS INC is more than five percent of the total outstanding common shares.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit 99
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

BlackRock, Inc.

Signature:	Spencer Fleming
Name/Title:	Managing Director
Date:	04/24/2026

Exhibit Information

Exhibit 24: Power of Attorney Exhibit 99: Item 7