Quick Takeaways
- WELLINGTON MANAGEMENT GROUP LLP filed SCHEDULE 13G/A for MBX Biosciences Common Stock (MBX).
- Disclosed ownership: 7.5%.
- Date of event: 31 Dec 2025.
WELLINGTON MANAGEMENT GROUP LLP - 31 Dec 2025 SCHEDULE 13G/A Report for MBX Biosciences Common Stock (MBX)
- Filing Manager
- WELLINGTON MANAGEMENT GROUP LLP
- Reporting Manager
- Wellington Management Group LLP
- Security
- MBX Biosciences Common Stock
- Symbol
- MBX
- Shares outstanding
- 44,666,147 shares
- Disclosed Ownership
- 3,349,961 shares
- Ownership
- 7.5%
- Form type
- SCHEDULE 13G/A
- Filing time
- 10 Feb 2026, 11:21:53 UTC
- Date of event
- 31 Dec 2025
- Previous filing
- 06 Oct 2025
- SEC
- View on sec.gov
Quoteable Key Fact
"WELLINGTON MANAGEMENT GROUP LLP disclosed 7.5% ownership in MBX Biosciences Common Stock (MBX) on 31 Dec 2025."
What Changed
- Previous schedule filing date: 06 Oct 2025.
- Current filing was accepted on 10 Feb 2026, 11:21.
Why This Matters
- This page explains what this Schedule 13D/13G filing tells you before manager-level rows.
- You can verify ownership claims directly against the original SEC filing.
Source Evidence
Backed by Schedule 13D/13G
See Original Filing
Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.
Reporting Managers (4)
| Name | Ownership | Shares Owned | sole voting power | shared voting power | Signature | Title | CIK |
|---|---|---|---|---|---|---|---|
| Wellington Management Group LLP | 7.5% | 3,349,961 | 0 | 3,189,892 | Taisia Lowe | Regulatory Analyst | |
| Wellington Group Holdings LLP | 7.5% | 3,349,961 | 0 | 3,189,892 | Taisia Lowe | Regulatory Analyst | |
| Wellington Investment Advisors Holdings LLP | 7.5% | 3,349,961 | 0 | 3,189,892 | Taisia Lowe | Regulatory Analyst | |
| Wellington Management Company LLP | 7.3% | 3,349,961 | 0 | 3,181,810 | Taisia Lowe | Regulatory Analyst |