A major pre-IPO venture backer is systematically reducing its stake, with over $24M in proposed and completed sales in the past month. This is a strong negative signal for near-term price support. Monitor for additional Form 144 filings and any lock-up expiration events.
Price Chart
Executive Summary
Third Rock Ventures V, L.P., a 10% stockholder, filed a Form 144 to sell 133,618 shares of Rapport Therapeutics common stock, valued at approximately $5.38 million. This follows recent insider sales totaling $18.7M over the past 30 days, signaling continued insider monetization.
Key Facts
- Third Rock Ventures V, L.P. (10% stockholder) intends to sell 133,618 shares of RAPP common stock.
- Estimated aggregate sale value: $5,378,124.50.
- Proposed sale date: May 11, 2026.
- Recent insider activity (30d): 4 sells totaling $18.7M.
- Third Rock has sold 702,518 shares in three separate transactions in the past month (April 17, May 7, May 8).
Financial Impact
Proposed sale of $5.38M by a major venture backer, adding to $18.7M in recent insider sales.
Risk Factors
- Continued insider selling by major shareholders could pressure the stock.
- Venture backer liquidation may signal lack of confidence in near-term catalysts or valuation.
- Potential for additional unregistered sales as Third Rock reduces its position.
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 3 SEC documents filed with EDGAR.
| Document | Accession Number |
|---|---|
| 144 Filing (Primary) | 0001974078-26-000178 |
| Document: 0001974078-26-000178-index.html | 0001974078-26-000178 |
| Document: 0001974078-26-000178.txt | 0001974078-26-000178 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 23, 2026 2d ago | Insider Cluster | $26.00 | awaiting T+5 | — | $25.93 (−0.27%) |
Oct 22, 2026 4d ago | Insider Cluster | $27.33 | awaiting T+5 | — | $25.93 (−5.12%) |
Oct 21, 2026 4d ago | Insider Buy | $26.53 | awaiting T+5 | — | $25.93 (−2.26%) |
Oct 20, 2026 6d ago | 8-K | $29.37 | awaiting T+5 | — | $25.93 (−11.71%) |
Oct 6, 2026 19d ago | 144 | $30.86 $28.33 | ▲ +8.20% | ▲ +7.22% | $25.93 (+15.98%) |
Oct 1, 2026 24d ago | Insider Cluster | $32.17 $30.65 | ▼ −4.72% | ▼ −5.89% | $25.93 (−19.40%) |
Aug 26, 2026 8w ago | Insider Cluster | $50.83 $47.65 | ▼ −6.26% | ▼ −6.52% | $25.93 (−48.99%) |
Aug 5, 2026 11w ago | 8-K | $42.44 $47.73 | ▲ +12.46% | ▲ +12.11% | $25.93 (−38.90%) |
Jul 1, 2026 16w ago | Insider Cluster | $38.97 $41.75 | ▲ +7.13% | ▲ +5.77% | $25.93 (−33.46%) |
Jun 30, 2026 16w ago | 144 | $39.39 $39.72 | ▲ +0.84% | ▲ +0.58% | $25.93 (−34.17%) |
US Market Status
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