Ciena

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-09-20 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: CIENA CORP (CIEN) CIK: 0000936395 --- Reporting Owner --- Name: Cumello Joseph CIK: 0001963638 Role: Officer (EVP & General Mgr.) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -441 | Price: $348.80 Total Value: $153,820.80 Shares Owned After: 42,431 | Ownership: D (Direct) Footnotes: [F1] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/13/2022. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 3 filed on 2/3/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #2] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -182 | Price: $348.80 Total Value: $63,481.60 Shares Owned After: 42,249 | Ownership: D (Direct) Footnotes: [F3] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 2/1/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 2/3/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #3] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -582 | Price: $348.80 Total Value: $203,001.60 Shares Owned After: 41,667 | Ownership: D (Direct) Footnotes: [F4] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/12/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/14/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #4] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -180 | Price: $348.80 Total Value: $62,784.00 Shares Owned After: 41,487 | Ownership: D (Direct) Footnotes: [F5] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/16/2025. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/18/2025. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #5] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -331 | Price: $348.80 Total Value: $115,452.80 Shares Owned After: 41,156 | Ownership: D (Direct) Footnotes: [F6] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/17/2024. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/19/2024. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). --- Footnotes (Complete Index) --- F1: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/13/2022. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 3 filed on 2/3/2023. F2: Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). F3: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 2/1/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 2/3/2023. F4: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/12/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/14/2023. F5: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/16/2025. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/18/2025. F6: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/17/2024. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/19/2024. --- Signature --- /s/ By: Michelle Rankin For: Joseph Cumello (2026-09-21)