Form 4: Tourmaline Bio Director Gifts Common Shares

Tourmaline Bio Director Caley Castelein reported a gift of 522 common shares, reducing his direct beneficial ownership.

Summary

• Caley Castelein, a Director of Tourmaline Bio, Inc. (TRML), reported a transaction on October 15, 2025.
• The transaction involved a gift (Code G) of 522 shares of common stock at a price of $0.
• Following this transaction, Caley Castelein directly beneficially owns 515,997 shares of common stock.
• Additionally, Caley Castelein indirectly beneficially owns 431,939 shares held by KVP Capital, LP.
• Caley Castelein is the Managing Member of KVP Capital GP, LLC, the General Partner of KVP, and has sole voting and investment power over shares held by KVP, though he disclaims beneficial ownership except for his pecuniary interest.

Sentiment

Score: 5

Explanation: The filing details a routine insider transaction where a director gifted a small number of shares. This type of transaction is generally neutral in terms of market sentiment as it does not reflect on the company's operational performance or strategic direction.

Future Outlook

NA

Industry Context

NA

Related Party Transactions

• The filing notes an in-kind distribution of shares by KVP Capital, LP to its limited partner for no consideration, which represented a change in the form of the Reporting Person's ownership.

Key Dates

Recommendation

This Form 4 reports a routine insider transaction involving a gift of shares by a director. Such a transaction, particularly for a relatively small number of shares and without consideration, typically does not provide new information that would warrant a change in investment recommendation. The overall investment thesis for Tourmaline Bio, Inc. remains unchanged based solely on this filing.

Keywords

Tourmaline Bio, TRML, Caley Castelein, Form 4, insider transaction, share ownership, director