Arista Networks (NYSE: ANET) delivered a quarter that makes "beat" feel inadequate. Revenue hit $3.66 billion, 58.5% above the prior year and roughly $330 million ahead of the company's own $3.3 billion guidance. Non-GAAP diluted EPS of $1.20 topped the $1.08 consensus by 11%. This is the highest year-over-year revenue growth since Arista's IPO, per management.
Product revenue drove everything, surging 67% to $3.19 billion from $1.91 billion a year ago. Service revenue grew 18% to $467.6 million. The mix shift toward product cuts both ways: it juices top-line growth but compresses gross margins, since services carry higher margins. GAAP gross margin fell 100 basis points year over year to 63.6%, and non-GAAP gross margin dropped 120bps to 64.0%. That compression is structural, not cyclical. It reflects the product mix, not cost inflation or pricing pressure. Operating leverage more than compensated: GAAP operating margin expanded 250bps to 44.9%, and non-GAAP operating margin rose 50bps to 49.1%, a record.
The beat was not a one-off. Arista's Q4 guidance calls for revenue of $3.9 billion to $4.0 billion, implying sequential growth of roughly 7% to 9% and year-over-year growth of 49% to 53% at the midpoint. Non-GAAP diluted EPS is guided to $1.26–$1.30, which would represent 44% to 48% growth from Q4 2025. The guidance range is tight — a $100 million spread on a $4 billion midpoint suggests visibility is strong.
AI is the story. Arista launched open Ethernet rack-scale architectures (ESUN and Etherlink SU-144) for scale-up and scale-out AI networks, partnering with AMD, Arm, Broadcom, Meta, Microsoft, Qualcomm, and d-Matrix. The company also detailed its scale-across networking strategy for distributed AI fabrics, targeting deployments of up to one million XPUs. These are not press-release vaporware. They are product announcements with named partners and specific technical specs. The timing aligns with the broader industry shift from InfiniBand to Ethernet for AI back-end networks, a trend that plays directly to Arista's strengths.
Capital allocation was quiet. No share repurchases occurred in the first nine months of 2026, compared to $983 million in buybacks in the same period last year. Cash and marketable securities grew to $14.4 billion from $10.7 billion at year-end 2025, and total assets crossed $25 billion for the first time. With no debt and a fortress balance sheet, the absence of buybacks is notable but not alarming. Management may be conserving firepower for strategic investments or M&A, though no deals were announced.
The S&P 100 addition in September 2026 marks Arista's maturation from high-growth disruptor to blue-chip incumbent. The stock now trades at roughly 40x trailing earnings, a premium the growth trajectory supports but that leaves little room for execution missteps.
What to watch next quarter: whether gross margin stabilizes as product mix normalizes, whether the Q4 guidance midpoint proves conservative or aggressive, and whether the company resumes buybacks or deploys cash toward acquisitions. For now, Arista is executing at a level few hardware companies can match, and the AI demand driving this run shows no sign of fading.