William Blair Investment Management, Llc - Sep 30, 2025 SCHEDULE 13G/A Report for MERCURY SYSTEMS INC Common Stock (MRCY)

Filing Manager: William Blair Investment Management, Llc
Reporting Manager: WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC
Security: MERCURY SYSTEMS INC Common Stock
Symbol: MRCY
Shares outstanding: 60.1M shares
Disclosed Ownership: 2.53M shares
Ownership: 4.2%
Form type: SCHEDULE 13G/A
Date filed: 11/12/2025, 06:24 PM
Date of event: Sep 30, 2025
Previous filing: Jul 30, 2025
SEC: View on sec.gov

Reporting Managers (1)

Name	Ownership	Shares Owned	sole voting power	shared voting power	Signature	Title	CIK
WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC	4.2%	2.53M	2.25M	0	Walter R. Randall, Jr.	Chief Compliance Officer