Ciena vs. ADTRAN: Which Optical Networking Stock is the Better Buy?

Ciena and ADTRAN are both benefiting from strong demand for optical networking solutions driven by AI and data-center investments. Ciena shows stronger fundamentals with over $10B expected backlog extending into fiscal 2028, accelerating product adoption, and upward earnings revisions, earning a Zacks Rank #1 (Strong Buy). ADTRAN faces supply constraints, product-mix pressure, customer deployment timing issues, and significant downward earnings revisions, receiving a Zacks Rank #4 (Sell). Ciena trades at a higher valuation (16.98X Price/Book) compared to ADTRAN (4.54X), reflecting diverging growth trajectories.