🕵️ MBX Biosciences, Inc. ($MBX)
SEC insider & ownership activity, last 12 months · CIK 1776111 · every row links its SEC filing
Over the last 12 months insiders sold $2.7M against $13.1M of open-market buying. Patrick J. Heron bought $12.0M in discretionary trades (Sep). 1 planned sale is pending, the largest $7K (Azoulay Salomon). No red-flag 8-Ks in the window.
Monthly net open-market insider flow, last 12 months (up = net buying)
Insider flow
3 buyers, $13.1M (4 lots) · 2 sellers, $2.7M (4 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Patrick J. Heron | 1 | $12.0M | 0 | – | Sep 26, 2025 |
| Azoulay Salomon | 0 | – | 3 | $2.7M | May 8, 2026 |
| Hawryluk P. Kent | 2 | $798K | 1 | $18K | May 6, 2026 |
| Steven L. Hoerter | 1 | $265K | 0 | – | Oct 17, 2025 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Patrick J. Heron | 11.7% | 13D | Sep 26, 2025 | filing ↗ | |
| James N. Topper | 11.7% | 13D | Sep 26, 2025 | filing ↗ | |
| Frazier Life Sciences X, L.P. | 11.7% | 13D | Sep 26, 2025 | filing ↗ | |
| Fhmls X, L.P. | 11.7% | 13D | Sep 26, 2025 | filing ↗ | |
| Fhmls X, L.L.C. | 11.7% | 13D | Sep 26, 2025 | filing ↗ | |
| FMR LLC | 11.2% | 13G | Jul 8, 2026 | filing ↗ | |
| Abigail P. Johnson | 11.2% | 13G | Jul 8, 2026 | filing ↗ | |
| Wellington Management Group LLP | 10.5% | 13G | Jul 8, 2026 | filing ↗ | |
| Wellington Group Holdings LLP | 10.5% | 13G | Jul 8, 2026 | filing ↗ | |
| Wellington Investment Advisors Holdings LLP | 10.5% | 13G | Jul 8, 2026 | filing ↗ | |
| Wellington Management Company LLP | 9.8% | 13G | Jul 8, 2026 | filing ↗ | |
| Scott D. Sandell | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Ali Behbahani | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Carmen Chang | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Edward T. Mathers | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Forest Baskett | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Anthony A. Florence, JR. | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Mohamad H. Makhzoumi | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Paul Walker | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| New Enterprise Associates 17, L.P. | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| NEA Partners 17, L.P. | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| NEA 17 GP, LLC | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Rick Yang | 8.1% | 13D | Nov 6, 2025 | filing ↗ | |
| Orbimed Advisors LLC | 7.7% | 13D | Feb 5, 2026 | filing ↗ | |
| DEEP Track Capital, LP | 6.5% | 13G | Aug 14, 2025 | filing ↗ | |
| DEEP Track Biotechnology Master Fund, Ltd. | 6.5% | 13G | Aug 14, 2025 | filing ↗ | |
| David Kroin | 6.5% | 13G | Aug 14, 2025 | filing ↗ | |
| Orbimed Capital GP VII LLC | 6.3% | 13D | Feb 5, 2026 | filing ↗ | |
| Paradigm Biocapital Advisors LP | 5.2% | 13G | Jun 24, 2026 | filing ↗ | |
| Paradigm Biocapital Advisors GP LLC | 5.2% | 13G | Jun 24, 2026 | filing ↗ | |
| Senai Asefaw, M.D. | 5.2% | 13G | Jun 24, 2026 | filing ↗ |
Planned insider sales (Form 144)
| Seller | Planned | Approx. sale date | |
|---|---|---|---|
| Bartram Richard | $280K | Jun 10, 2026 | filing ↗ |
| Bartram Richard | $321K | Jun 9, 2026 | filing ↗ |
| Bartram Richard | $554K | May 13, 2026 | filing ↗ |
| Bartram Richard | $992K | May 11, 2026 | filing ↗ |
| Azoulay Salomon | $2.7M | May 8, 2026 | filing ↗ |
| Bartram Richard | $380K | May 8, 2026 | filing ↗ |
| Bartram Richard | $322K | May 7, 2026 | filing ↗ |
| Hawryluk P. Kent | $18K | May 6, 2026 | filing ↗ |
| Azoulay Salomon | $7K | May 6, 2026 | filing ↗ |
| Bartram Richard | $159K | May 1, 2026 | filing ↗ |
| Bartram Richard | $341K | Apr 22, 2026 | filing ↗ |
| Bartram Richard | $30K | Mar 25, 2026 | filing ↗ |
| Bartram Richard | $300K | Mar 16, 2026 | filing ↗ |
| James M. Cornelius | $1.1M | Jan 12, 2026 | filing ↗ |
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Officer/director changes (5.02) | Jul 9, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jun 12, 2026 | filing ↗ |
| Other events (8.01) | Jun 12, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jun 12, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jun 4, 2026 | filing ↗ |
| Shareholder vote (5.07) | Jun 4, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | May 11, 2026 | filing ↗ |
| Other events (8.01) | May 11, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 11, 2026 | filing ↗ |
| Earnings (2.02) | May 7, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 7, 2026 | filing ↗ |
| Earnings (2.02) | Mar 12, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 12, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Mar 9, 2026 | filing ↗ |
| Other events (8.01) | Mar 9, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Mar 9, 2026 | filing ↗ |
| Material agreement (1.01) | Feb 24, 2026 | filing ↗ |
| Officer/director changes (5.02) | Feb 24, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 24, 2026 | filing ↗ |
| Other events (8.01) | Feb 4, 2026 | filing ↗ |
| Officer/director changes (5.02) | Jan 20, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 20, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 20, 2026 | filing ↗ |
| Earnings (2.02) | Jan 11, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jan 11, 2026 | filing ↗ |
| Other events (8.01) | Jan 11, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jan 11, 2026 | filing ↗ |
| Earnings (2.02) | Oct 31, 2025 | filing ↗ |
| Officer/director changes (5.02) | Oct 31, 2025 | filing ↗ |
| Material agreement (1.01) | Sep 24, 2025 | filing ↗ |