MBX Biosciences, Inc. has 22 Schedule 13D or 13G filings on record since 2025-08-12. 7 holders' latest filing reports 5% or more of common stock, $0.0001 par value per share. Each figure below is the holder's own, as filed, with the filing linked.
Holders
| Holder | Percent | Shares | Latest | Event date |
|---|---|---|---|---|
| Frazier Life Sciences Public Fund, L.P. | 11.7% | 1,429,573 | SCHEDULE 13D/A, 2026-08-10 | 2026-08-06 |
| Fmr LLC | 11.2% | 5,322,885 | SCHEDULE 13G/A, 2026-07-08 | 2026-06-30 |
| Wellington Management Group LLP | 10.5% | 4,977,523 | SCHEDULE 13G/A, 2026-07-08 | 2026-06-30 |
| New Enterprise Associates 17, L.P. | 8.1% | 3,614,486 | SCHEDULE 13D/A, 2025-11-10 | 2025-11-06 |
| Orbimed Advisors LLC | 6.4% | 3,074,853 | SCHEDULE 13D/A, 2026-08-10 | 2026-08-06 |
| BlackRock, Inc. | 5.5% | 2,628,181 | SCHEDULE 13G, 2026-07-29 | 2026-06-30 |
| Paradigm BioCapital Advisors LP | 5.2% | 2,493,015 | SCHEDULE 13G, 2026-06-24 | 2026-06-16 |
| Norwest Venture Partners XVI, LP | 4.8% | 2,136,335 | SCHEDULE 13D/A, 2025-09-30 | 2025-09-26 |
| Wellington Biomedical Innovation Master Investors (Cayman) II, L.P. | 4.5% | 2,017,394 | SCHEDULE 13G/A, 2025-11-12 | 2025-09-30 |
| P. Kent Hawryluk | 4.3% | 1,995,759 | SCHEDULE 13G/A, 2025-11-14 | 2025-09-30 |
| Deep Track Capital, LP | 3.64% | 1,732,569 | SCHEDULE 13G/A, 2026-08-14 | 2026-06-30 |
Purpose of Transaction (Item 4)
Frazier Life Sciences Public Fund, L.P.
Item 4 is hereby amended to remove references to "FLSPOF" and the "FLSPOF Shares" from the first paragraph.Item 4 of the SCHEDULE 13D/A filed 2026-08-10
Orbimed Advisors LLC
The Reporting Persons from time to time intend to review their investment in the Issuer on the basis of various factors, including the Issuer's business, financial condition, results of operations and prospects, general economic and industry conditions, the securities markets in general and those for the Issuer's Shares in particular, as well as other developments and other investment opportunities. Based upon such review, the Reporting Persons will take such actions in the future as the Reporting Persons may deem appropriate in light of the circumstances existing from time to time. If the Reporting Persons believe that further investment in the Issuer is attractive, whether because of the market price of Shares or otherwise, they may acquire Shares or other securities of the Issuer either in the open market or in privately negotiated transactions. Similarly, depending on market and other factors, the Reporting Persons may determine to dispose of some or all of the Shares currently owned by the Reporting Persons or otherwise acquired by the Reporting Persons either in the open market or in privately negotiated transactions. Except as set forth in this Schedule 13D, the Reporting Persons have not formulated any plans or proposals which relate to or would result in: (a) the acquisition by any person of additional securities of the Issuer or the disposition of securities of the Issuer, (b) an extraordinary corporate transaction, such as a merger, reorganization or …The first part of Item 4 of the SCHEDULE 13D/A filed 2026-08-10; the filing has the rest
New Enterprise Associates 17, L.P.
NEA 17 acquired the NEA 17 Shares for investment purposes. Depending on market conditions, its continuing evaluation of the business and prospects of the Issuer and other factors, NEA 17 and the other Reporting Persons may dispose of or acquire additional shares of the Issuer. Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in: (a) The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer; (b) An extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) A sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) Any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board; (e) Any material change in the present capitalization or dividend policy of the Issuer; (f) Any other material change in the Issuer's business or corporate structure; (g) Changes in the Issuer's charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person; (h) Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered …The first part of Item 4 of the SCHEDULE 13D/A filed 2025-11-10; the filing has the rest
Timeline
| Filed | Holder | Percent | Filing |
|---|---|---|---|
| 2025-08-12 | Wellington Management Group LLP | 6.8% | SCHEDULE 13G/A |
| 2025-08-14 | Deep Track Capital, LP | 6.55% | SCHEDULE 13G/A |
| 2025-08-20 | Frazier Life Sciences Public Fund, L.P. | 13.6% | SCHEDULE 13D/A |
| 2025-09-30 | Orbimed Advisors LLC | 9% | SCHEDULE 13D/A |
| 2025-09-30 | Frazier Life Sciences Public Fund, L.P. | 11.7% | SCHEDULE 13D/A |
| 2025-09-30 | Norwest Venture Partners XVI, LP | 4.8% | SCHEDULE 13D/A |
| 2025-10-06 | Wellington Management Group LLP | 10.8% | SCHEDULE 13G/A |
| 2025-11-10 | New Enterprise Associates 17, L.P. | 8.1% | SCHEDULE 13D/A |
| 2025-11-12 | Wellington Biomedical Innovation Master Investors (Cayman) II, L.P. | 4.5% | SCHEDULE 13G/A |
| 2025-11-14 | P. Kent Hawryluk | 4.3% | SCHEDULE 13G/A |
| 2026-01-21 | BlackRock, Inc. | 5.1% | SCHEDULE 13G |
| 2026-02-10 | Wellington Management Group LLP | 7.5% | SCHEDULE 13G/A |
| 2026-02-11 | Orbimed Advisors LLC | 7.7% | SCHEDULE 13D/A |
| 2026-04-27 | BlackRock, Inc. | 4.8% | SCHEDULE 13G/A |
| 2026-05-06 | Fmr LLC | 6.2% | SCHEDULE 13G |
| 2026-06-24 | Paradigm BioCapital Advisors LP | 5.2% | SCHEDULE 13G |
| 2026-07-08 | Fmr LLC | 11.2% | SCHEDULE 13G/A |
| 2026-07-08 | Wellington Management Group LLP | 10.5% | SCHEDULE 13G/A |
| 2026-07-29 | BlackRock, Inc. | 5.5% | SCHEDULE 13G |
| 2026-08-10 | Orbimed Advisors LLC | 6.4% | SCHEDULE 13D/A |
| 2026-08-10 | Frazier Life Sciences Public Fund, L.P. | 11.7% | SCHEDULE 13D/A |
| 2026-08-14 | Deep Track Capital, LP | 3.64% | SCHEDULE 13G/A |
Tools for this story
Each opens in a new tab, filled in for MBX Biosciences, Inc.. With no account yet, you sign up free and land on the result.
Where this comes from
Anyone who comes to own more than 5% of a class of a listed company's voting shares has to tell the SEC. A holder who may seek to change or influence the company files Schedule 13D, and has to say in Item 4, "Purpose of Transaction", what it intends to do. A holder with no such intent, such as many index and passive funds, may file the shorter Schedule 13G. Both are amended when the stake changes, including when it falls below 5%.
Every row here is one of those filings, linked to the filing itself. Percentages and share counts are exactly as the holder filed them, for the holder the filing names; an amendment showing a lower figure is shown as filed. Item 4 text is quoted word for word. Where a 13D's Item 4 contains a sentence stating a definite intent to influence the company, that sentence is marked and quoted; the page does not describe the holder or its motives beyond the words it filed. Nothing here is investment advice.