Arista, Synopsys named top buy-and-hold AI stocks

The Motley Fool's case rests on a simple split: companies building chatbots or cutting-edge chips may not be the biggest AI winners from here, while the businesses supporting the underlying infrastructure could be. Arista Networks sits in the cabling and switches that shuttle data among thousands of accelerators and servers, and in 2026 it surpassed $3 billion in quarterly revenue for the first time and joined the Fortune 500. Its new 7060XE7 switches, with air- and liquid-cooled options, aim to move more data between AI chips while fitting more computing power into each rack. The article notes cloud infrastructure providers and enterprise customers rarely replace networking vendors once systems are in place, which could support the strategy over time.

Synopsys takes the other choke point: the electronic design automation software engineers use to turn ideas into silicon blueprints. As chips grow more complex, testing, debugging, and tuning have ballooned, and Synopsys is applying its own AI to that problem. In July it announced agentic AI workflows built with Microsoft and used by Advanced Micro Devices, and at this year's DAC it showcased fully autonomous, long-running agents for chip verification and electronics system design on its AgentEngineer platform and Nvidia's AI infrastructure. If those tools become embedded in customers' workflows, each new wave of AI hardware could deepen its moat.

For investors with a 10-year horizon, the article frames these as buy-and-hold candidates rather than speculative trades, but position sizing still matters. The outcome hinges on whether AI infrastructure spending keeps growing and whether these companies keep their footing, since AI spending cycles, competition, and customer concentration can all introduce share-price volatility.