Two AI Infrastructure Stocks That Crushed the Market

Arista Networks and Comfort Systems USA have delivered extraordinary returns over the past decade, turning $1,000 investments into $31,072 and $46,954 respectively, vastly outpacing the S&P 500's $3,222 return. Both companies benefit from the AI data center boom, with Arista supplying high-speed networking switches and Comfort Systems handling construction, cooling, and mechanical systems. Arista posted $9 billion in FY2025 revenue while Comfort Systems crossed $1 billion in net income with a record $11.94 billion backlog. Both trade at premium valuations, with risks including hyperscaler spending slowdowns, tariffs, and inflation pressures on fixed-price contracts.