New York, Jan 27, 2026, 2:12 PM ET — Regular session
- Arista Networks shares rose roughly 2% Tuesday, adding to a 5.4% gain from the previous day.
- Microsoft’s launch of the Maia 200 AI chip, paired with a bullish analyst note, put the spotlight on the Ethernet infrastructure powering AI clusters.
- Attention now shifts to Microsoft’s earnings on Jan. 28, followed by Arista’s quarterly report on Feb. 12.
Arista Networks Inc (ANET.N) saw its shares climb $2.90, or nearly 2%, to $146.62 in afternoon trading Tuesday. This marks a second day of gains, pushing the stock up before a heavy slate of major tech earnings. The rally puts Arista’s market value at around $183 billion.
Why it matters now: investors are circling back to AI infrastructure as a “show me” trade, demanding clear evidence that Big Tech’s heavy spending is driving growth. This week’s earnings from Microsoft and other megacaps are crucial, given their data-center strategies directly impact suppliers providing AI hardware. 1
On Monday, Microsoft unveiled its Maia 200 inference accelerator, highlighting a systems design that relies on a two-tier scale-up network “built on standard Ethernet” — the high-speed connections linking chips in an AI cluster. For networking vendors, Ethernet remains the recurring theme. 2
Wells Fargo analyst Aaron Rakers called Microsoft’s launch a “derivative positive” for Arista and chipmaker Marvell Technology, pointing to broader ripple effects beyond just the processor. He also noted that Microsoft’s move toward in-house chips might reduce its dependence on Nvidia eventually. 3
Microsoft described Maia 200 as “the most efficient inference system” it has launched, boasting roughly 30% better performance per dollar compared to current systems. Deployments are already underway in its U.S. Central cloud region, with plans to expand to other regions. 4
Arista jumped 5.4% on Monday, closing at $143.72, and climbed further on Tuesday as buyers stayed aggressive. 5
Other AI-related infrastructure stocks also posted gains. Microsoft added roughly 2.3%, and Marvell edged up close to 2%. Networking rival Cisco Systems jumped about 1.8%, while optical gear provider Ciena surged nearly 6%.
Arista specializes in client-to-cloud networking equipment used in major AI and cloud data centers, plus campus and routing networks. This niche has turned the stock into a popular choice for investors betting on AI data-center expansions without jumping into chipmakers. 6
Arista is gearing up to release its quarter-ending Dec. 31 results after U.S. markets close on Feb. 12. The company plans a conference call at 4:30 p.m. ET that day. 7
But the setup can backfire just as quickly. A two-day rally might stall if earnings guidance falls short or if customers delay deployments to absorb new chip launches and capacity limits.
Traders have their eyes on Microsoft’s upcoming report first. The company plans to release its fiscal second-quarter results after the market closes on Wednesday, Jan. 28. Investors will be keen for insights on AI capital expenditures and the Maia 200 rollout—details that could reshape forecasts across the entire supply chain. 8
Arista’s next key date is Feb. 12. This week’s momentum will hinge on orders, margins, and any shifts in sentiment regarding Ethernet-based AI clusters. 9
