Julie Rubinstein, President and COO of Adaptive Biotechnologies Corp (NASDAQ:ADPT), filed a Form 4 on October 29, 2026, disclosing the exercise of stock options and sale of common shares across three trading days from October 27 through October 29, 2026, under a Rule 10b5-1 trading plan.

Key Highlights

  • Three days of option exercises: Rubinstein exercised 11,881 stock options on each of October 27, 28, and 29, 2026, at an exercise price of $12.14 per share.
  • Shares sold across all three days: A total of 35,443 shares were disposed of via sale transactions on October 27, 28, and 29, 2026, at weighted average prices ranging from $26.58 to $28.90 per share.
  • Remaining direct ownership: Following all reported transactions, Rubinstein directly holds 377,802 shares of common stock.
  • Remaining option position: After the three option exercises, 130,276 stock options remain beneficially owned, with an expiration date of March 4, 2032.
  • Rule 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.
  • Options fully vested: The filing states the exercised stock options were fully vested and exercisable at the time of exercise.

Rubinstein's Three-Day Option Exercise and Share Sale Activity at Adaptive Biotechnologies

According to the Form 4 filing, Julie Rubinstein, serving as President and Chief Operating Officer of Adaptive Biotechnologies Corp, carried out a series of transactions over October 27, 28, and 29, 2026. On each day, she exercised 11,881 stock options at an exercise price of $12.14, acquiring the equivalent number of common shares. The options, which the filing notes were fully vested and exercisable, carry an expiration date of March 4, 2032. Following all three exercises, 130,276 stock options remain in her direct beneficial ownership.

Concurrent with each exercise, Rubinstein disposed of shares through open-market sales. On October 27, she sold 3,000 shares at a weighted average price of $26.58 (ranging from $26.04 to $27.02) and 8,881 shares at a weighted average price of $27.53 (ranging from $27.07 to $27.98). On October 28, she sold 11,681 shares at a weighted average price of $28.44 (ranging from $27.85 to $28.84) and 200 shares at a weighted average price of $28.90 (ranging from $28.88 to $28.92). On October 29, she sold 11,881 shares at a weighted average price of $28.27 (ranging from $27.92 to $28.73).

The filing discloses that all transactions were conducted pursuant to a Rule 10b5-1 trading plan that Rubinstein adopted on November 18, 2025. The filing also notes that weighted average sale prices are available in full detail upon request to the company, any security holder, or SEC staff. After all reported activity, Rubinstein's direct beneficial ownership of common stock stands at 377,802 shares.

What Was Disclosed

The filing reported the exercise of stock options totaling 35,643 shares and the sale of 35,443 shares of Adaptive Biotechnologies common stock by President and COO Julie Rubinstein over three consecutive trading days, all under a pre-established Rule 10b5-1 plan.