Wellington Management Group Llp - Sep 30, 2025 SCHEDULE 13G/A Report for MBX Biosciences, Inc. Common Stock (MBX)

Filing Manager
Wellington Management Group Llp
Reporting Manager
Wellington Management Group LLP
Security
MBX Biosciences, Inc. Common Stock
Symbol
MBX
Shares outstanding
44.7M shares
Disclosed Ownership
4.82M shares
Ownership
10.8%
Form type
SCHEDULE 13G/A
Date filed
10/6/2025, 12:22 PM
Date of event
Sep 30, 2025
Previous filing
Aug 12, 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 10.8% 4.82M 0 4.56M Taisia Lowe Regulatory Analyst
Wellington Group Holdings LLP 10.8% 4.82M 0 4.56M Taisia Lowe Regulatory Analyst
Wellington Investment Advisors Holdings LLP 10.8% 4.82M 0 4.56M Taisia Lowe Regulatory Analyst
Wellington Management Company LLP 10.6% 4.82M 0 4.56M Taisia Lowe Regulatory Analyst