Form 4: Third Rock Ventures Sells Rapport Therapeutics Stock

Third Rock Ventures V, L.P. and Third Rock Ventures VI, L.P. reported transactions involving the sale of Rapport Therapeutics, Inc. common stock.

Summary

• Third Rock Ventures V, L.P. sold 271,495 shares of Rapport Therapeutics common stock on May 7, 2026, at a weighted average price of $40.12 per share, with individual sales ranging from $40.00 to $40.60.
• Following this transaction, Third Rock Ventures V, L.P. directly beneficially owned 6,437,733 shares.
• On May 8, 2026, Third Rock Ventures V, L.P. sold an additional 5,018 shares at a weighted average price of $40.30 per share, with individual sales ranging from $40.10 to $40.80.
• After the second transaction, Third Rock Ventures V, L.P. directly beneficially owned 6,432,715 shares.
• Third Rock Ventures VI, L.P. beneficially owns 969,218 shares indirectly.

Sentiment

Score: 4

Explanation: StockSavvy.ai views this as a neutral to slightly negative sentiment due to significant share sales by a major stakeholder, although executed under a pre-planned trading strategy.

Negatives

• Significant sale of shares by a major stakeholder, Third Rock Ventures V, L.P., indicating a potential reduction in their direct stake in Rapport Therapeutics.

Future Outlook

The filing does not contain forward-looking statements or guidance. It reports on past transactions.

Management Comments

• The reported transactions were effected pursuant to a Rule 10b5-1 trading plan dated November 21, 2025, previously adopted by the Reporting Person.
• The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $40.00 to $40.60, inclusive.
• The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
• Each of TRV GP V and TRV GP V LLC disclaims beneficial ownership of the shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares.
• Each of Reporting Persons disclaims the existence of a Section 13(d) 'group' as between any TRV V related parties and any TRV VI related parties and this report shall not be deemed an admission that any of such parties is or may be part of such a group with any of the other parties.

Industry Context

StockSavvy.ai notes that Form 4 filings are standard disclosures for changes in beneficial ownership by insiders and significant shareholders. The execution of these sales under a Rule 10b5-1 plan suggests pre-planned divestitures rather than reactions to recent company events.

Stakeholder Impact

• Shareholders may view the significant sales by Third Rock Ventures V, L.P. as a potential indicator of reduced confidence or a need for liquidity, which could influence market sentiment.
• The sales are conducted under a Rule 10b5-1 plan, which is designed to provide an affirmative defense against allegations of insider trading, suggesting a structured approach to divestment.

Key Dates

Keywords

Form 4, SEC Filing, Insider Trading, Stock Sale, Beneficial Ownership, Third Rock Ventures, Rapport Therapeutics, Common Stock, Rule 10b5-1