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Schedule 13G/A

CIEN Schedule 13G/A filing by BlackRock

BlackRock reported beneficial ownership of 14.5M shares, representing 12% of CIENA CORP in this filing.

FiledDec 4, 2025
Ownership dateNov 30, 2025
Reported shares14.5M
Reported ownership12%
Ownership details

Voting and dispositive power reported in the filing

These figures describe the reporting filer’s disclosed voting and investment authority. They should be read together with the reported share count and percentage.

Sole voting power 13.7M
Shared voting power 14.5M
Sole dispositive power 14.5M
Shared dispositive power 14.5M
Price context

Price dates alongside the ownership filing

Price data provides market context around the disclosure. It does not identify the filer’s actual transaction price.

Close near filing date$195.73as of Dec 4, 2025
Latest tracked price$417.01as of Aug 5, 2026
Source

Original filing and accession

Use the SEC filing as the primary source when you need the complete disclosure, footnotes, exhibits, or reporting-person details.

Reporting filer
BlackRock
CIK
CIK0002012383
Accession
0002012383-25-002995
Form
Schedule 13G/A
Open SEC filing View CIEN ownership history
Read the filing in context

Understand what a Schedule 13 filing does—and does not—tell you.

How to read a Schedule 13G → Does a 13G mean the shares were just bought? → Filing date vs. ownership date →