Regeneron Co-CSO Andrew Murphy Exercises Expiring Options & Sells Under 10b5-1 Plan

Executive Summary

On October 15, 2026, Andrew J. Murphy, Co-Chief Scientific Officer of Regeneron Pharmaceuticals, Inc. ($REGN), filed Form 4 disclosing the exercise of expiring stock options and related open-market share sales executed pursuant to a Rule 10b5-1 trading plan adopted on May 7, 2026.

Transaction Breakdown

1. Option Exercise (October 13, 2026):

   • Exercised non-qualified stock options for 17,000 shares of Common Stock at an exercise price of $381.92 per share.
   • The option award was nearing its expiration date of December 16, 2026.

2. Tax Withholding / Net Settlement (October 13, 2026):

   • Surrendered 12,853 shares back to the company at $754.58 per share (total value of ~$9.70M) to cover exercise costs and tax obligations (Transaction Code: F).

3. Open Market Dispositions (October 14, 2026):

   • Sold the net remaining balance of 4,147 shares across multiple tranches at weighted-average prices ranging from $753.76 to $781.47 (weighted average price of approximately $772.71 per share).
   • Total gross proceeds from open-market sales: ~$3,204,412.

Holdings & Context

• Pre vs. Post Ownership: Following the completion of the exercise and sales, Dr. Murphy's direct holdings remain at 47,833 shares, exactly equal to his direct holding balance prior to the option exercise. He additionally holds 4,414 shares indirectly through the company 401(k) plan.
• Significance Assessment: Low. The transactions represent a standard cashless exercise-and-sell pattern to monetize an equity award expiring within two months, conducted entirely under a pre-scheduled Rule 10b5-1 plan with zero reduction in the insider's baseline equity holding.