Julie Rubinstein, President and COO of Adaptive Biotechnologies Corp (NASDAQ:ADPT), filed a Form 4 on October 26, 2026, disclosing option exercises and common stock sales conducted between October 22 and October 26, 2026, pursuant to a Rule 10b5-1 trading plan.

Key Highlights

  • Three option exercise dates: Rubinstein exercised 11,881 stock options on each of October 22, 23, and 26, 2026, at an exercise price of $12.14 per share.
  • Total shares disposed: Across the three days, Rubinstein sold a combined 35,643 shares of common stock in multiple separate transactions.
  • Sale price range: Weighted average sale prices across the six sell transactions ranged from $24.38 to $26.30, with individual transaction price ranges spanning as low as $23.82 and as high as $26.42.
  • Remaining beneficial ownership: Following all reported transactions, Rubinstein directly owned 377,802 shares of common stock.
  • Remaining options: After the three exercises, 165,919 stock options (right to buy, expiring 03/04/2032) remained beneficially owned directly by Rubinstein.
  • 10b5-1 plan: According to the filing, all transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by Rubinstein on November 18, 2025.

Rubinstein's October 2026 Option Exercises and Share Sales at Adaptive Biotechnologies

According to the filing, Julie Rubinstein, serving as President and Chief Operating Officer of Adaptive Biotechnologies Corp, carried out a series of transactions in the company's common stock over three consecutive trading days. On each of October 22, 23, and 26, 2026, Rubinstein exercised 11,881 fully vested stock options at an exercise price of $12.14, acquiring shares under transaction code "M." The filing notes that the options are fully vested and exercisable, with an expiration date of March 4, 2032.

On each of the same three days, Rubinstein sold shares under transaction code "S." On October 22, two sell transactions disposed of 10,181 shares at a weighted average price of $24.38 and 1,700 shares at a weighted average price of $25.29. On October 23, sells covered 4,500 shares at a weighted average of $24.50 and 7,381 shares at a weighted average of $25.28. On October 26, 8,503 shares were sold at a weighted average of $25.94 and 3,378 shares at a weighted average of $26.30. The filing discloses that each reported price is a weighted average and that the underlying transactions occurred across price ranges; full details are available upon request to the company or SEC staff.

The filing states that all transactions were made pursuant to a Rule 10b5-1 trading plan that Rubinstein adopted on November 18, 2025. Following the completion of all reported activity, Rubinstein's direct beneficial ownership stood at 377,802 shares of common stock and 165,919 remaining stock options. The Form 4 was signed by Kyle Piskel as Attorney-in-Fact on October 26, 2026.

What Was Disclosed

Rubinstein's Form 4 disclosed nine transactions in Adaptive Biotechnologies common stock and three option exercises between October 22 and October 26, 2026, all conducted under a pre-established Rule 10b5-1 plan, with a resulting direct ownership of 377,802 shares.