Officer and Director Stock Transactions

This filing details stock transactions by Julie Rubinstein, President and COO of Adaptive Biotechnologies Corp. Between April 17 and April 21, 2026, Rubinstein engaged in several transactions involving the company's common stock. These included the acquisition of shares at prices around $8.46 and $12.14, and the disposal of shares at weighted average prices ranging from $14.14 to $15.13. The transactions were executed under a Rule 10b5-1 trading plan. Additionally, the filing reports on the exercise and disposal of stock options. The options exercised were for common stock with exercise prices of $8.46 and $12.14. Following these transactions, Rubinstein's post-transaction holdings of common stock were 395,146 shares, and her holdings of stock options amounted to 379,777 shares.