Arista earnings: revenue rises 58.5% to $3.66 billion in Q3

Arista earnings for the third quarter of 2026 show revenue of about $3.66 billion, up 58.5% from a year earlier, according to the results Arista Networks filed on November 3. The company says that is its fastest year-over-year growth since its IPO, and well above the $3.3 billion it had guided to.

Arista sells the Ethernet switches that connect servers inside data centers, including the ones that train and run AI models. Its quarterly numbers are one of the clearer readings of how much money is going into AI networking.

Revenue and profit in the third quarter

Revenue was $3,657.6 million, against $2,308.3 million in the third quarter of 2025. Arista says it rose 20.5% from the second quarter of 2026.

Product revenue, mostly switches, was $3,190.0 million, up from $1,911.7 million. Service revenue was $467.6 million, up from $396.6 million.

Gross margin slipped by about a point, while operating margin rose because operating expenses grew more slowly than revenue. They were $683.3 million, up from $512.0 million. Research and development was the biggest line at $486.9 million.

Non-GAAP figures leave out items such as stock-based compensation and gains on investments. GAAP EPS is higher than non-GAAP this quarter in part because of a $134.5 million gain on strategic investments, which Arista counts in GAAP net income and removes from the non-GAAP figure. Other income, net, was $273.1 million, up from $98.9 million.

Fourth-quarter outlook

For the fourth quarter of 2026, Arista expects:

• Revenue of $3.9 billion to $4.0 billion.
• Non-GAAP operating margin of 48% to 49%.
• Non-GAAP diluted EPS of $1.26 to $1.30.

These are the company's own estimates, not results.

Balance sheet and cash flow

At September 30, Arista held $2,288.1 million in cash and $12,070.9 million in marketable securities. Inventories were $3,209.8 million, up from $2,247.1 million at the end of 2025. Current deferred revenue, money billed for products and services not yet recognized as revenue, was $5,102.2 million, up from $4,002.6 million.

Over the first nine months of 2026, operating cash flow was $3,977.4 million, against $3,110.0 million a year earlier. Arista did not repurchase any stock in that period. In the first nine months of 2025 it spent $983.0 million on buybacks.

What Arista says about AI

CEO Jayshree Ullal said the quarter showed Arista's "increased relevance for the generative and agentic AI era." The release lists three product and business items:

• Arista, working with AMD, Arm, Broadcom, d-Matrix, Meta, Microsoft and Qualcomm, launched open rack-scale designs for AI networks. The Etherlink SU-144 design supports up to 144 accelerators per rack in a single hop, and up to 1,024 chips across racks.
• It described a "scale-across" approach for linking AI data centers in different locations, up to one million chips.
• It said it is using AI tools built with Anthropic, Google and OpenAI to find security vulnerabilities in its own software earlier.

Arista was also added to the S&P 100 index in September 2026.

What the release does not say

The release gives no revenue split by customer or by AI versus other uses, so the AI share of the $3.66 billion is not in these numbers. It also names no customers. The company's risk section notes that a limited number of customers make up a substantial portion of revenue, and cites component supply and tariffs as risks.

Arista holds its earnings call at 1:30 p.m. Pacific time on November 3, with a replay on its investor relations site.