Form 4: Quantum-Si Director Sells Shares for Estate Planning

Quantum-Si Director and 10% owner Jonathan M. Rothberg sold 26,095 shares of Class A Common Stock for estate planning purposes at an average price of $3.07 per share.

Summary

• Jonathan M. Rothberg, a Director and 10% owner of Quantum-Si Inc. (QSI), disposed of 26,095 shares of Class A Common Stock.
• The transaction occurred on October 16, 2025, at a weighted average sales price of $3.07 per share, with individual sales ranging from $3.07 to $3.09 per share.
• This sale was executed in connection with estate planning, pursuant to a Rule 10b5-1 trading plan established by Dr. Rothberg on September 13, 2024.
• Following this transaction, Dr. Rothberg continues to beneficially own 2,568,443 shares of Class A Common Stock directly.
• Indirect beneficial ownership of Class A Common Stock totals 11,138,235 shares through various LLCs (NVR TR, LLC, JNR TR, LLC, GBR TR, LLC, EJR TR, LLC, JAR TR, LLC), 23rd Century Capital LLC, and Bonnie E Gould Rothberg MD.
• Indirect beneficial ownership of Class B Common Stock totals 19,937,500 shares through 4C Holdings I, LLC and 4C Holdings V, LLC.

Sentiment

Score: 5

Explanation: The transaction is a pre-planned insider sale for estate planning purposes, which is generally considered a neutral event and does not reflect a change in the company's operational performance or outlook.

Future Outlook

No specific future outlook or guidance is provided in this insider transaction report.

Management Comments

• The sale was effected in connection with estate planning pursuant to a 10b5-1 trading plan established by Dr. Rothberg on September 13, 2024.

Industry Context

This filing reports an individual insider transaction and does not contain information related to broader industry trends or competitive landscape.

Related Party Transactions

• Shares of Class A common stock previously held by 2012 JMR Trust Common, LLC were distributed for estate planning purposes to NVR TR, LLC, JNR TR, LLC, GBR TR, LLC, and EJR TR, LLC. Dr. Rothberg is the sole manager of these LLCs.
• Dr. Rothberg is the sole manager of 4C Holdings I, LLC, 4C Holdings V, LLC, and JAR TR, LLC.
• Dr. Rothberg is the spouse of Bonnie E. Gould Rothberg MD, who holds Class A Common Stock.
• Dr. Rothberg's son is the manager of 23rd Century Capital LLC, which holds Class A Common Stock. Dr. Rothberg disclaims beneficial ownership of shares held by his spouse and 23rd Century Capital LLC.

Stakeholder Impact

• Shareholders: A minor reduction in direct insider ownership, but as a pre-planned sale for estate planning, it is generally not interpreted as a negative signal regarding the company's future prospects.

Key Dates

Recommendation

The filing details a pre-planned insider sale for estate planning, which is a neutral event and does not provide new information regarding the company's fundamentals or future prospects. Investors should hold their positions and await further operational or financial updates.

Keywords

Quantum-Si, QSI, Jonathan Rothberg, Insider Transaction, Form 4, Stock Sale, Estate Planning, 10b5-1 Plan, Director, 10% Owner