Regeneron Pharmaceuticals Director Kathryn Guarini Files Form 144 for $360K Stock Sale

Transaction Overview

Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) Director Kathryn Guarini filed a Form 144 notice on October 30, 2026, disclosing the planned sale of 400 shares of common stock with an aggregate market value of $360,000.00 (implying an approximate price of $900.00 per share).

Key Transaction Details

• Securities to be Sold: 400 common shares.
• Origin of Shares: Acquired via stock option exercise from the issuer on October 30, 2026, paid in cash.
• Pre-Arranged Trading Plan: The transaction is executed pursuant to a Rule 10b5-1 trading plan adopted on February 13, 2026.
• Broker: UBS Financial Services, Inc.

Past 3 Months Selling Activity

Director Guarini has engaged in regular, planned sales over the preceding three months:

• August 10, 2026: Sold 400 shares for gross proceeds of $320,000.00.
• September 2, 2026: Sold 400 shares for gross proceeds of $340,000.00.

Market Impact & Significance

The trading significance of this filing is categorized as Low. The proposed sale represents a negligible fraction of the company's 101,630,713 outstanding common shares. Given that the transaction is conducted under a pre-established Rule 10b5-1 plan following an option exercise, it reflects standard programmatic liquidity rather than a directional sentiment shift on company fundamentals.