Arista Q3 results jump 58.5% to $3.66 billion

AI networking demand gave Arista Networks its fastest year-over-year growth since going public. Arista Q3 results printed revenue of $3.6576 billion, up 58.5% from a year earlier and 20.5% from the prior quarter, with GAAP operating margin of 44.9% and non-GAAP operating margin of 49.1%.

What happened

GAAP diluted EPS was $1.22 and non-GAAP diluted EPS $1.20. For the fourth quarter, Arista guided revenue to $3.9–$4.0 billion and non-GAAP EPS to $1.26–$1.30. The company noted it was added to the S&P 100 in September 2026, according to its official release.

SiliconANGLE said the quarter beat Street estimates near $3.33 billion in sales and $1.08 in EPS, with shares up more than 9% after hours. The Q4 midpoint near $3.95 billion implies about 59% growth and sits above a Street view near $3.65 billion in revenue and $1.16 in EPS.

Together with Super Micro's server beat the same evening, the print reinforces that AI infrastructure spending is still showing up in both compute boxes and the switches that stitch them together.

Operating margins near 45% GAAP and 49% non-GAAP leave Arista with a profitability profile that few AI hardware suppliers can match at this growth rate, which is why the after-hours jump exceeded 9% even before U.S. cash trading resumed.

Why it matters

Networking is often the quieter leg of the AI buildout, but these margins show it can be more profitable than the box assemblers. Our coverage of the Broadcom Anthropic SPV financing wave underlined how much custom silicon and fabric spend still sits ahead of hyperscalers.

Equity beta remains the near-term risk. A Nasdaq chip rebound earlier in October proved how quickly semiconductor sentiment can reverse; Arista Q3 results will be tested against that same midterm-driven Nasdaq futures tape.

S&P 100 inclusion also widens the forced-buyer and index-fund audience just as AI-regulation chatter after the midterms could cut the other way on multiples.

Hyperscaler fabric upgrades and Ethernet-versus-proprietary debates will decide how durable that growth is once the initial AI cluster build wave seasons into a more replacement-driven cycle. Adding Arista to the S&P 100 in September 2026 also widens passive ownership just as active managers debate whether networking multiples can stay elevated through a political cycle less friendly to Big Tech.

What's next

Watch whether the $3.9–$4.0 billion Q4 guide holds through any post-election AI-capex second-guessing. Arista's Q3 release details revenue, margins, EPS and outlook.

If Arista Q3 results keep the stock bid while Nasdaq futures stay soft, networking may temporarily lead the AI hardware complex.

Competitors in merchant silicon and white-box switching will face sharper questions about share once these growth rates are in the rear-view.

Peer networking and merchant-silicon results over the next two weeks will show whether Arista's 58.5% growth is company-specific share gain or a sector-wide AI switching boom.