Thesis. First $3 billion quarter, full-year guidance raised to 40% growth, and more than 100 Etherlink AI customers — with deferred revenue ballooning because Arista cannot get enough silicon to ship. The Ethernet champion is supply-constrained, not demand-constrained.
Reviewed 11 September 2026, after Q2 2026 results. Next review after Q3 earnings on 3 November 2026.
What it does
Arista builds high-performance Ethernet switches for datacentres — the boxes that route traffic between servers — plus EOS, a single software image that runs across the entire product line, and CloudVision for managing it.
It holds number one share in datacentre Ethernet above 10G, having passed Cisco. AI scale-out fabrics are the growth engine.
The software is the moat, not the hardware. One operating system across every switch means a customer who standardises on Arista finds it painful to leave — which is unusual leverage in a market that otherwise competes on price per port.
Bull case
- Q2 2026, reported 4 August: revenue $3.036B, up 37.7% and 12.1% sequentially — the first $3 billion quarter, and well above the $2.8B guide
- Profitability is expanding. Non-GAAP EPS $1.02 (+39.7%), non-GAAP operating margin 49.9% from 48.8%
- Full-year guidance raised hard — to $12.6B and 40% growth, from a $10.5B target set in July. Q3 guided to around $3.3B
- Etherlink AI switches now exceed 100 cumulative customers, with 1.6 Tbps AI fabric platforms and the 7060XE7 series introduced
- Ethernet is beating InfiniBand for AI fabrics, which is Arista's home ground
- Growth is broadening geographically. International reached 23% of revenue from 15.5%, with EMEA up 55%
- A new market is being sized. Arista puts the "Scale-Across" segment at a $15–20B addressable market by 2030
Bear case
- It cannot ship what it has sold. Wafer fab shortages, semiconductor supply de-commits and lead times beyond 52 weeks are capping deliveries. Deferred product revenue jumped around $643M to $3.63B — customers have paid for hardware Arista can't deliver
- The market read that as bad news. The stock fell on the print despite the raise, on concern that bottlenecks delay upside and pressure margins
- Two customers dominate. Microsoft and Meta have each historically been above 10% of revenue and together a very large share of the cloud business. Both have the scale to design their own switches or buy white-box
- It doesn't control its own chip. Arista buys switch silicon from Broadcom
- NVIDIA now sells the network too. Spectrum-X puts the GPU vendor directly into Arista's market
- Gross margin is drifting down — 63.4%, against 65.6% a year earlier, with component cost and mix pressure flagged
- Competition has re-energised with HPE-Juniper combined and Cisco pushing back
Major customers
- Microsoft and Meta — historically each above 10% of revenue and disclosed as such, together representing a very large share of the cloud titan business. Current percentages should be verified against the latest annual filing
- Oracle and other cloud titans
- Large enterprise and financial services — lower concentration and higher margin, and the diversification that would de-risk the model
Read-through — this one runs in both directions and both matter.
Upstream: Arista buys its switch silicon from AVGO. Broadcom's Tomahawk and Jericho commentary is a direct leading indicator for Arista's product availability and cost, and Arista does not control the chip it depends on.
Downstream: Microsoft and META capex guidance is the demand signal. Meta in particular has swung Arista's growth rate materially in past cycles. Both are also capable of buying white-box hardware from CLS, which makes the concentration risk sharper than it looks.
The pattern: deferred revenue of $3.63B is effectively a backlog proxy, and it doubled. This is the same shape as VRT — demand outrunning the ability to deliver. When two names in different categories show it at once, the constraint is the build-out itself, not either company.
What would change the view
- Deferred product revenue — whether it keeps climbing, which means the supply constraint is worsening
- Gross margin against the component cost and mix pressure already flagged
- Any Microsoft or Meta volume shift toward white-box or in-house designs
- Spectrum-X wins and losses against Arista in AI fabrics
- Enterprise diversification as a share of revenue
- Broadcom's silicon availability, which caps what Arista can ship regardless of demand
Update log
- 11 Sep 2026 — Reviewed. Verdict held at Constructive.
- 4 Aug 2026 — Q2 2026 results: revenue $3.036B (+37.7%), non-GAAP EPS $1.02, operating margin 49.9%, FY26 guidance raised to $12.6B. Supply constraint became the central fact — deferred product revenue up $643M to $3.63B on wafer shortages and 52-week-plus lead times. Etherlink passed 100 cumulative customers.
- 25 Jul 2026 — Full review.
Research and education only — not investment advice.
Made with Bullet