Regeneron Pharmaceuticals, Inc. director George L. Sing filed a Form 144 notice of proposed sale with the SEC on November 2, 2026, covering 21,129 shares of common stock with an aggregate market value of $20,376,359.76.

Key Highlights

  • Seller: George L. Sing, identified as a Director of Regeneron Pharmaceuticals, Inc.
  • Shares proposed for sale: 21,129 shares of common stock, with an aggregate market value of $20,376,359.76.
  • Shares outstanding: 101,630,713 shares of common stock reported outstanding at the time of filing.
  • Approximate date of sale: November 2, 2026, through Morgan Stanley Smith Barney LLC Executive Financial Services, 1 New York Plaza, 8th Floor, New York, NY 10004.
  • Acquisition sources: Shares to be sold were acquired through multiple option exercises under a registered plan on November 2, 2026, and previously exercised options dated as early as May 3, 2024.
  • No sales in prior 3 months: The filing reports nothing to report under securities sold during the past 3 months.

George Sing's Proposed Share Sale at Regeneron Pharmaceuticals

According to the Form 144 filing, George L. Sing, a director of Regeneron Pharmaceuticals, Inc. (NASDAQ:REGN), filed notice of a proposed sale of 21,129 shares of common stock on November 2, 2026. The filing lists the aggregate market value of those shares at $20,376,359.76, with 101,630,713 total shares of common stock outstanding at the time of filing. The proposed sale is to be executed through Morgan Stanley Smith Barney LLC Executive Financial Services.

The filing details ten separate acquisition transactions underlying the shares proposed for sale. Six of these transactions are listed as "Exercise of Options Under a Registered Plan," all dated November 2, 2026, and acquired from the issuer for cash consideration. The share amounts from those six transactions are 2,610, 2,479, 2,480, 2,480, 2,610, and 2,610, respectively. Four additional lots are described as "Previously Exercised Options," acquired from the issuer on December 30, 2025 (3,024 shares), January 2, 2026 (323 shares), May 3, 2024 (1,123 shares), and December 31, 2024 (1,390 shares), each paid for in cash.

The filing states that no securities of the issuer were sold by Sing during the past three months. The notice is dated November 2, 2026, and is signed by George L. Sing. By signing, the filer represented, as stated in the form, that he "does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed."

What Was Disclosed

Regeneron director George L. Sing filed a Form 144 on November 2, 2026, proposing to sell 21,129 common shares with an aggregate market value of $20,376,359.76, acquired through option exercises and previously exercised options, via Morgan Stanley Smith Barney LLC.