Vanguard Portfolio Management filed a Schedule 13G with the SEC on October 30, 2026, disclosing beneficial ownership of 5,417,946 shares of Builders FirstSource Inc common stock as of September 30, 2026.

Key Highlights

  • Aggregate beneficial ownership: Vanguard Portfolio Management reported beneficial ownership of 5,417,946 shares of Builders FirstSource Inc common stock.
  • Percent of class: The reported stake represents 5.03% of the class of securities.
  • Sole dispositive power: Vanguard Portfolio Management holds sole power to dispose of all 5,417,946 shares reported.
  • Sole voting power: Sole voting power is held over 60,372 shares, with shared voting power reported as 0.
  • Triggering date: The date of the event requiring the filing is stated as September 30, 2026.
  • Affiliates included: The filing covers securities beneficially owned by Vanguard Portfolio Management LLC and affiliates Vanguard Fiduciary Trust Company and Vanguard Global Advisers, LLC.

Vanguard Portfolio Management Crosses 5% Threshold in Builders FirstSource

According to the Schedule 13G filed on October 30, 2026, Vanguard Portfolio Management, organized in Pennsylvania and headquartered at 100 Vanguard Blvd, Malvern, PA 19355, disclosed an aggregate beneficial ownership position of 5,417,946 shares of common stock in Builders FirstSource Inc (NYSE:BLDR), the issuer headquartered at 2001 Bryan Street, Suite 1600, Dallas, TX 75201. The filing was triggered by an event dated September 30, 2026.

The filing reports that Vanguard Portfolio Management holds sole dispositive power over all 5,417,946 shares and sole voting power over 60,372 shares. Shared voting power and shared dispositive power are each reported as 0. The filing states that the reported stake represents 5.03% of the class. The filing is classified under reporting person type "IA," indicating an investment adviser, and was signed by My Trieu-Gatt, identified as Authorized Signatory, Head of Global Fund Administration.

In accordance with SEC Release No. 34-39538 (January 12, 1998), the filing notes that the reported securities include those beneficially owned by Vanguard Portfolio Management LLC and affiliates Vanguard Fiduciary Trust Company and Vanguard Global Advisers, LLC. The filing also states that "investment companies registered under the Investment Company Act of 1940 and other managed accounts, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities reported herein," and that no single other person's interest in the reported securities exceeds 5%. The filer certified the securities were acquired and held in the ordinary course of business and not for the purpose of changing or influencing control of the issuer.

What Was Disclosed

Vanguard Portfolio Management filed a Schedule 13G reporting beneficial ownership of 5,417,946 shares, or 5.03%, of Builders FirstSource Inc common stock as of September 30, 2026, with sole dispositive power over all reported shares and sole voting power over 60,372 shares.