Form 4: ADPT COO Sells Shares Under Pre-Planned 10b5-1 Plan

Adaptive Biotechnologies' President and COO, Julie Rubinstein, executed pre-planned option exercises and subsequent sales of company stock.

Summary

• Julie Rubinstein, President and COO of Adaptive Biotechnologies Corp (ADPT), reported multiple transactions involving company common stock and stock options.
• Transactions occurred on March 3, 4, and 5, 2026, and were executed pursuant to a Rule 10b5-1 trading plan adopted on November 18, 2025.
• On March 3, 2026, Rubinstein acquired 14,722 shares by exercising options at $6.55 per share and 11,881 shares at $12.14 per share.
• On March 3, 2026, she disposed of 24,423 shares at a weighted average price of $15.49 and 6,518 shares at a weighted average price of $16.33.
• On March 4, 2026, Rubinstein acquired 14,722 shares by exercising options at $6.55 per share and 11,881 shares at $12.14 per share.
• On March 4, 2026, she disposed of 30,941 shares at a weighted average price of $16.60.
• On March 5, 2026, Rubinstein acquired 14,722 shares by exercising options at $6.55 per share and 11,881 shares at $12.14 per share.
• On March 5, 2026, she disposed of 30,941 shares at a weighted average price of $16.00.
• Following these transactions, Rubinstein's direct beneficial ownership of common stock decreased from 602,971 shares (before the first sale on March 3, 2026) to 575,235 shares.
• The number of beneficially owned derivative securities (stock options) also decreased due to the exercises.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral event, typical for executive compensation and personal financial planning, especially given the pre-planned nature under a 10b5-1 plan, which reduces speculative interpretation.

Positives

• The exercise of stock options indicates that the options were in-the-money, allowing the executive to realize value.
• All reported transactions were conducted under a pre-established Rule 10b5-1 trading plan, which suggests planned financial management rather than a reaction to recent non-public information.

Negatives

• The transactions resulted in a net decrease in the direct beneficial ownership of common stock by a key executive, which can sometimes be perceived negatively by investors.

Future Outlook

No specific forward-looking statements or guidance were provided in this Form 4 filing, which is typical for an insider transaction report.

Industry Context

StockSavvy.ai notes that insider transactions, particularly sales executed under a Rule 10b5-1 plan, are common for executives managing their personal portfolios. These plans allow insiders to sell shares at predetermined times or prices, mitigating concerns about trading on material non-public information and are a standard practice across various industries, including biotechnology.

Comparison to Industry Standards

• StockSavvy.ai observes that such pre-planned sales are a standard practice among executives across various industries, including biotechnology, to diversify holdings and manage liquidity. There are no specific comparable companies, projects, or results mentioned in this filing to provide a direct comparison.

Stakeholder Impact

• Shareholders might observe a slight decrease in direct insider ownership, but the pre-planned nature of the sales under a 10b5-1 plan generally minimizes negative interpretation regarding management's confidence in the company's future.

Next Steps

• Ongoing vesting of options with an exercise price of $12.14, with 1/48 of such shares vesting at the end of each full month of continuous service until fully vested.

Key Dates

Recommendation

The insider transactions, while involving significant share sales, were conducted under a pre-established 10b5-1 trading plan. This suggests a routine diversification and liquidity event rather than a reaction to new material information, thus not warranting a change in investment thesis based solely on this filing.

Keywords

Adaptive Biotechnologies, ADPT, Julie Rubinstein, Insider Trading, Form 4, Stock Option Exercise, Stock Sale, 10b5-1 Plan, Beneficial Ownership