Ciena

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-03-26 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: CIENA CORP (CIEN) CIK: 0000936395 --- Reporting Owner --- Name: Claflin Bruce L. CIK: 0001403694 Role: Director --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-03-26 | Code: A (Grant or award) Shares: +605 | Price: $0.00 Shares Owned After: 50,843 | Ownership: D (Direct) Footnotes: [F1] Restricted stock units (RSUs) vest in full on the first anniversary of the date of the grant. [F2] Shares reported include unvested Restricted Stock Units (RSUs). --- Holdings --- [Holding #1] Security: Common Stock Ownership: I (Indirect) Footnotes: [F3] The beneficiaries of the trust are the reporting person's spouse and children. The reporting person disclaims beneficial ownership of the securities held by the trust. --- Footnotes (Complete Index) --- F1: Restricted stock units (RSUs) vest in full on the first anniversary of the date of the grant. F2: Shares reported include unvested Restricted Stock Units (RSUs). F3: The beneficiaries of the trust are the reporting person's spouse and children. The reporting person disclaims beneficial ownership of the securities held by the trust. --- Signature --- /s/ By: Michelle Rankin For: Bruce L. Claflin (2026-03-27)