Monitor for actual execution of these sales on Form 4 filings. The combined Atlas Venture filings, alongside 9 other insider sells in the past 30 days totaling $10.2M, suggest a pattern of insider distribution. While the dollar amount is not large relative to market cap, the signal from a lead venture investor trimming is notable. Watch for any clinical data readouts or pipeline updates that could alter the selling rationale.
Price Chart
Executive Summary
Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund I, L.P., two affiliated venture capital funds, filed Form 144 notices on June 29, 2026, indicating intent to sell a combined 102,969 shares of Dyne Therapeutics (DYN) valued at approximately $2.16 million. As early investors, these sales represent a partial exit by a major insider, though the dollar amount is modest relative to DYN's $3.5B market cap.
Key Facts
- Atlas Venture Fund XI, L.P. files Form 144 to sell 102,969 shares of DYN common stock.
- Atlas Venture Opportunity Fund I, L.P. also files a Form 144 on the same date (share count not specified in available text).
- Total proposed sale value is approximately $2,156,170.86 based on the first filing.
- Shares were acquired in a private placement on July 31, 2020.
- The filing is an advance notice of intent to sell; the actual sale may not occur.
- Recent insider activity (30d) shows 9 sells totaling $10.2M, indicating ongoing insider selling pressure.
Financial Impact
Proposed sale of ~102,969 shares worth ~$2.16M, representing a small fraction of DYN's $3.5B market cap.
Risk Factors
- Insider selling by a major early investor may signal reduced confidence in near-term catalysts.
- Additional unregistered sales by affiliates could add overhang.
- The company has no approved products; clinical-stage biotech risk is elevated.
Market Snapshot
Investment Themes
Documents Analyzed
This report is based on 4 SEC documents filed with EDGAR.
| Document | Accession Number |
|---|---|
| 144 Filing (DYN) — Batch item 1 | 0001628280-26-046094 |
| Document: 0001628280-26-046094-index.html | 0001628280-26-046093 |
| Document: 0001628280-26-046094.txt | 0001628280-26-046094 |
| 144 Filing (DYN) — Batch item 4 | 0001628280-26-046093 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
Aug 17, 2026 6w ago | Insider Cluster | $26.15 $17.90 | ▲ +31.55% | ▲ +29.57% | $15.20 (+41.87%) |
Aug 14, 2026 6w ago | 144 | $26.15 $18.52 | ▼ −29.18% | ▼ −27.65% | $15.20 (−41.87%) |
Aug 13, 2026 7w ago | 144 | $25.70 $18.52 | ▲ +27.94% | ▲ +25.95% | $15.20 (+40.86%) |
Aug 13, 2026 7w ago | 144 | $25.70 $18.52 | ▼ −27.94% | ▼ −25.95% | $15.20 (−40.86%) |
Aug 13, 2026 7w ago | 144 | $25.70 $18.52 | ▼ −27.94% | ▼ −25.95% | $15.20 (−40.86%) |
Jul 29, 2026 9w ago | Press Release | $25.73 $26.09 | ▲ +1.40% | ▼ −2.57% | $15.20 (−40.92%) |
Jul 22, 2026 10w ago | Press Release | $23.21 $26.78 | ▼ −15.38% | ▼ −12.48% | $15.20 (+34.51%) |
Jul 20, 2026 10w ago | 8-K | $23.45 $26.15 | ▲ +11.51% | ▲ +7.39% | $15.20 (−35.18%) |
Jun 30, 2026 13w ago | Insider Cluster | $21.79 $25.10 | ▲ +15.19% | ▲ +17.38% | $15.20 (−30.24%) |
Jun 29, 2026 13w ago | 144 | $22.21 $25.63 | ▼ −15.40% | ▼ −16.43% | $15.20 (+31.56%) |
US Market Status
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