Executive Summary: Ciena delivered a solid fiscal Q2 2025, with total revenue of $1.13 billion and a continuation of robust demand across cloud providers and service providers. Cloud provider revenue reached a record level, accounting for 38% of total revenue and rising 85% year over year to exceed $400 million in a single quarter, underscoring AI infrastructure investments and the company’s leadership in coherent optical solutions. Management signaled durable demand dynamics, including two notable cloud wins involving regional GPU clustering and data-center out-of-band management, alongside ongoing strength in North American Tier-1 service providers and international markets. Offsetting these positives were near-term margin headwinds driven by product mix (notably RLS and coherent pluggables) and a tariff environment that management estimates at approximately $10 million per quarter—a drag that is expected to be largely mitigated but recur in a dynamic tariff regime. The company raised FY2025 revenue growth guidance to ~14% (from prior ranges) while placing gross margin at the low end of 42-44% for the year, with an expectation of gradual improvement into 2026 and 2027 as Pluggables, RLS, and WaveLogic mix progressively normalize margins. Ciena also highlighted a strong balance sheet posture (cash and equivalents near $950M, net debt ~$639M) and substantial free cash flow generation ($128M in Q2), which supports ongoing share repurchase activity and strategic investments in R&D and capacity. Investors should monitor cloud-provider diversification, the rate of ramp for 800ZR/1.6T solutions, MoFEN pipeline expansion beyond India, and the trajectory toward mid-40s gross margins as products scale and mix shifts toward higher-margin offerings.