Ciena $CIEN falls 9% despite Q2 beat; guidance raise seen as insufficient after AI-sector rally

Ciena ($CIEN) fell approximately 8.9% in premarket trading on June 4, 2026, dragging the entire optical networking sector lower, despite reporting Q2 FY2026 results that beat consensus on both lines. The move reflects an expectations gap: solid results, but not the “more material beat and raise” analysts had priced in following a sector-wide AI rally.

Q2 FY2026 results: revenue of $1.57 billion, up 40% year-over-year, beating consensus; adjusted EPS of $1.64 versus the $1.46 estimate — a 12.3% upside surprise. Full-year FY2026 revenue guidance was raised to $6.3 billion plus or minus $100 million, representing 32% year-over-year growth at the midpoint.

The stock fell because earlier in the week Nvidia CEO Jensen Huang singled out Marvell as a potential “next trillion-dollar company,” lifting expectations across AI networking hardware names sharply. Ciena's guidance raise did not sustain that elevated bar. Sector peers fell in sympathy: Lumentum -4.2%, Coherent -5.6%, Marvell -6.5%, Corning -4.5%.

Ciena's core product is coherent optical networking equipment used in AI data center interconnects and metro/long-haul carrier networks — a direct beneficiary of hyperscaler infrastructure buildout. Full details in the SEC Form 8-K press release (June 4, 2026). Next earnings expected September 2026.

Not investment advice. Verify all figures with primary sources before acting.