Arista Networks $ANET ( ▲ 8.74% ) ripped higher Thursday, putting the AI data center networking name on track for its best session of the year so far.
The move looks heavily tied to options positioning, not a single clean headline catalyst.
Options traders are going all-in
By late morning, call buying in Arista was nearly 2x its 10-day moving average for a full session.
And that matters because call buying has basically become the retail trader’s favorite playbook in recent years, since it creates leveraged upside exposure and can amplify a stock’s move when momentum kicks in.
This had all the fingerprints of that kind of flow-driven rally.
No obvious headline, but the setup has been building
There wasn’t one breakout “news event” explaining the surge, but Arista has been getting more attention in recent weeks.
Earlier this month, Goldman Sachs flagged Arista as a top tactical earnings season trade, saying the stock could rise ~20% over the next year.
“ANET is well positioned amidst ongoing data center spending growth, where its position as a best of breed provider of networking equipment should advantage the company, particularly as data center networks become increasingly complex,” Goldman wrote in its January 8 note.
Translation: if hyperscaler capex stays hot, Arista stays one of the cleanest picks-and-shovels plays.
Microsoft data center expansion adds fuel to the narrative
Another big underlying tailwind is Microsoft.
Per Goldman, Microsoft accounted for ~20% of Arista’s revenue in 2024, and reports suggest Microsoft is planning a major expansion of its Wisconsin data center project, with preliminary approval tied to a $13.3B buildout in Mount Pleasant.
That’s exactly the kind of capex story that keeps Arista in the sweet spot: networking gear is not optional when the data center footprint expands.
This move was not “macro beta”
What made Thursday’s action stand out is that Arista popped without similar moves in peers like Cisco or Hewlett Packard.
Even after strong economic data at 8:30 a.m., this looked Arista-specific, which reinforces the idea that this was driven by positioning + AI data center enthusiasm, not just “stocks up = tech up.”
Bottom line
Arista didn’t need a clean headline catalyst.
Between surging call demand, Goldman pushing it as a tactical earnings trade, and Microsoft’s continued data center buildout momentum, $ANET had the perfect ingredients for a flow-driven upside breakout.