Vanguard Portfolio Management LLC filed an amended beneficial ownership statement with the SEC on October 30, 2026, disclosing a 4.88% stake in Lantheus Holdings Inc as of September 30, 2026.

Key Highlights

  • Aggregate beneficial ownership: Vanguard Portfolio Management reported 3,189,870 shares of Lantheus Holdings Inc common stock beneficially owned.
  • Percent of class: The reported holdings represent 4.88% of the outstanding class of common stock.
  • Sole voting power: Vanguard Portfolio Management holds sole voting power over 60,159 shares, with 0 shares subject to shared voting power.
  • Sole dispositive power: The filing discloses sole dispositive power over 3,189,870 shares, with no shared dispositive power reported.
  • Triggering event date: The date of the event requiring this filing is stated as September 30, 2026.
  • Filing type: This is Amendment No. 1 to the original statement, signed by My Trieu-Gatt, Authorized Signatory, Head of Global Fund Administration.

Vanguard's Disclosed Position in Lantheus Holdings Common Stock

According to the filing, Vanguard Portfolio Management LLC, organized in Pennsylvania and headquartered at 100 Vanguard Blvd, Malvern, PA 19355, reported an aggregate beneficial ownership of 3,189,870 shares of Lantheus Holdings Inc common stock, representing 4.88% of the class. The filing identifies the reporting person as an investment adviser, consistent with the classification under Rule 13d-1(b)(1)(ii)(E). Lantheus Holdings Inc, the issuer, is a medical imaging and diagnostics company with principal executive offices located at 201 Burlington Rd, South Building, Bedford, MA 01730, and its common stock carries CUSIP number 516544103.

The filing notes, in accordance with SEC Release No. 34-39538 dated January 12, 1998, that this statement reflects securities beneficially owned or deemed to be beneficially owned by Vanguard Portfolio Management LLC and certain of its affiliates, specifically Vanguard Fiduciary Trust Company and Vanguard Global Advisers, LLC. The statement covers securities held by Vanguard funds or sleeves thereof over which Vanguard Portfolio Management LLC exercises dispositive power, as well as securities held by clients over which the named affiliates exercise dispositive and/or voting power. The filing states that no single other person's interest in the reported securities exceeds 5%.

The certification accompanying the filing states that the securities "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." The statement was signed on October 30, 2026, by My Trieu-Gatt in the capacity of Authorized Signatory, Head of Global Fund Administration.

What Was Disclosed

Vanguard Portfolio Management LLC filed Amendment No. 1 to its beneficial ownership statement covering 3,189,870 shares of Lantheus Holdings Inc common stock, equal to 4.88% of the class, with a triggering event date of September 30, 2026.