Through the 90-day period concluding January 09, 2026, MBX Biosciences's top three insider stakeholders include Director Patrick J Heron (5.22Mn shares), TenPercentOwner Life Sciences X, L.P. Frazier (4.55Mn shares), Director Edward T Mathers (3.61Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Patrick J Heron | 5,219,440 | 30 Sep, 2025 | |
| Life Sciences X, L.P. Frazier | 4,552,774 | 17 Sep, 2024 | |
| Scott D Sandell | 3,614,486 | 17 Sep, 2024 | |
| Forest Baskett | 3,614,486 | 17 Sep, 2024 | |
| Edward T Mathers | 3,614,486 | 17 Sep, 2024 | |
| Enterprise Associates 17, L.P. New | 3,614,486 | 17 Sep, 2024 | |
| Carmen Chang | 3,614,486 | 17 Sep, 2024 | |
| Paul Edward Walker | 3,614,486 | 17 Sep, 2024 | |
| Anthony A. Jr. Florence | 3,614,486 | 17 Sep, 2024 | |
| Ali Behbahani | 3,614,486 | 17 Sep, 2024 | |
| Mohamad Makhzoumi | 3,614,486 | 17 Sep, 2024 | |
| Rick Yang | 3,614,486 | 17 Sep, 2024 | |
| Tiba Aynechi | 2,136,335 | 17 Sep, 2024 | |
| Biomedical Innovation Master Investors (Cayman) Ii L.P. Wellington | 1,790,122 | 17 Sep, 2024 | |
| P. Kent Hawryluk | President & Ceo | 1,112,533 | 28 Oct, 2025 |
| Carl L Gordon | 747,887 | 19 Feb, 2025 | |
| Advisors Llc Orbimed | 747,887 | 19 Feb, 2025 | |
| James M Cornelius | 102,082 | 17 Sep, 2024 | |
| Ora H. Pescovitz | 24,329 | 10 Apr, 2025 | |
| Steven L. Hoerter | 20,000 | 20 Oct, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 24 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 182,859 | $3.25 | 664,256 | D | M |
| 20 Oct, 2025 | P. Kent Hawryluk | Common Stock | A | 20,000 | $13.64 | 481,397 | D | P |
| 17 Oct, 2025 | Steven L. Hoerter | Common Stock | A | 20,000 | $13.25 | 20,000 | I | P |
| 26 Sep, 2025 | Patrick J Heron | Common Stock | A | 666,666 | $18.00 | 5,219,440 | I | P |
| 26 Sep, 2025 | Patrick J Heron | - | - | 5,219,440 | I | |||
| 08 Apr, 2025 | Ora H. Pescovitz | Common Stock | A | 7,693 | $5.89 | 24,329 | D | P |
| 08 Apr, 2025 | Ora H. Pescovitz | - | - | 24,329 | D | |||
| 18 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 49,070 | $10.84 | 3,255,000 | I | P |
| 18 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 94,100 | $10.84 | 747,887 | I | P |
| 18 Feb, 2025 | Carl L Gordon | Common Stock | A | 94,100 | $10.84 | 747,887 | I | P |
| 18 Feb, 2025 | Carl L Gordon | - | - | 747,887 | I | |||
| 18 Feb, 2025 | Carl L Gordon | Common Stock | A | 49,070 | $10.84 | 3,255,000 | I | P |
| 18 Feb, 2025 | Carl L Gordon | - | - | 3,255,000 | I | |||
| 14 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 29,540 | $9.85 | 3,205,930 | I | P |
| 14 Feb, 2025 | Advisors Llc Orbimed | Common Stock | A | 17,962 | $9.90 | 3,176,390 | I | P |
| 14 Feb, 2025 | Carl L Gordon | - | - | 3,176,390 | I | |||
| 14 Feb, 2025 | Carl L Gordon | Common Stock | A | 29,540 | $9.85 | 3,205,930 | I | P |
| 14 Feb, 2025 | Carl L Gordon | - | - | 3,205,930 | I | |||
| 14 Feb, 2025 | Carl L Gordon | Common Stock | A | 17,962 | $9.90 | 3,176,390 | I | P |
| 04 Feb, 2025 | P. Kent Hawryluk | Common Stock | A | 50,000 | $10.69 | 448,277 | I | P |