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

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