Form 4: Avidity CTO's PSU Vesting Boosts Stake, Tax Withholding Noted

Avidity Biosciences' Chief Technical Officer, Charles Calderaro III, increased his direct beneficial ownership by 13,524 shares following the vesting of performance-based restricted stock units and subsequent tax withholding on December 17, 2025.

Summary

• Charles Calderaro III, Chief Technical Officer of Avidity Biosciences, Inc., acquired 23,250 shares of common stock on December 17, 2025.
• These shares were obtained upon the vesting of performance-based restricted stock units (PSUs), which were originally granted on October 30, 2024.
• The PSUs were accelerated and settled on December 17, 2025, for tax planning purposes.
• Concurrently, 9,726 shares were withheld by Avidity Biosciences to cover tax withholding obligations related to the PSU settlement, at a price of $71.87 per share.
• Following these transactions, Charles Calderaro III directly beneficially owns 53,524 shares of Avidity Biosciences common stock.
• The acquired shares remain subject to recoupment by the Issuer if the Reporting Person's employment is terminated by the Issuer for cause or by the Reporting Person without good reason.

Sentiment

Score: 7

Explanation: The filing indicates an increase in insider ownership through the vesting of performance-based restricted stock units, which is generally a positive signal. However, a portion of shares was sold for tax withholding, a routine event that does not significantly alter the overall sentiment.

Positives

• Chief Technical Officer Charles Calderaro III increased his direct beneficial ownership of Avidity Biosciences common stock by a net of 13,524 shares (23,250 acquired minus 9,726 withheld for taxes).
• The vesting of performance-based restricted stock units generally indicates the achievement of pre-defined performance criteria, reflecting positively on the company's operational execution.

Negatives

• 9,726 shares were disposed of to cover tax withholding obligations, representing a reduction in the total shares acquired from the PSU vesting.

Risks

• Shares acquired upon PSU vesting are subject to recoupment by Avidity Biosciences if the Reporting Person's employment is terminated by the Issuer for cause or by the Reporting Person without good reason.

Future Outlook

N/A

Management Comments

• The performance-based restricted stock units were accelerated and settled on December 17, 2025, for tax planning purposes.

Industry Context

N/A

Related Party Transactions

• The vesting and settlement of performance-based restricted stock units (PSUs) and the subsequent withholding of shares for tax purposes represent transactions between Avidity Biosciences and its Chief Technical Officer, Charles Calderaro III, as part of his executive compensation.

Stakeholder Impact

• Shareholders: The net increase in direct beneficial ownership by a key executive can be viewed as a positive signal of management's continued alignment with shareholder interests and confidence in the company's future.
• Employees: The vesting of PSUs demonstrates the company's executive compensation structure, which may influence employee perception of equity incentives and performance-based rewards.

Key Dates

Recommendation

This Form 4 details a routine insider transaction involving the vesting of performance-based restricted stock units and subsequent tax withholding. While it shows a net increase in the Chief Technical Officer's direct beneficial ownership, it does not present new information that would fundamentally alter the investment thesis or warrant a change in stock recommendation. Investors should continue to monitor broader company performance and market conditions.

Keywords

Avidity Biosciences, RNA, Form 4, Insider Transaction, Stock Vesting, Restricted Stock Units, PSU, Executive Compensation, Charles Calderaro III, Chief Technical Officer