BlackRock, Inc. Increases Stake in Arrowhead Pharmaceuticals to 12.2%

BlackRock, Inc. has filed a Schedule 13G/A with the SEC, dated April 24, 2026, disclosing a significant increase in its stake in Arrowhead Pharmaceuticals Inc (ARWR). As of the event date on March 31, 2026, BlackRock reported beneficial ownership of 17,104,084 shares of common stock, representing 12.2% of the company. This marks a substantial increase from the previously reported 0.0% ownership, indicating a major new position or accumulation. The filing specifies that BlackRock holds sole voting power over 16,769,679 shares and sole dispositive power over the full 17,104,084 shares. The securities were acquired in the ordinary course of business and are not intended to influence or change the control of the issuer. Various subsidiaries under the BlackRock umbrella are involved in the holding, though no individual person's interest exceeds 5% of the total outstanding common shares. This amendment (No. 5) solidifies BlackRock's position as a major institutional shareholder in the biotechnology firm.