Comfort Systems stock is up nearly 20% today. And here’s why.

Comfort Systems shares look hot.

The heating, ventilation and air conditioning company’s stock has soared recently, jumping nearly 18% on Friday to extend 2025 and all-time highs; Shares recently traded at around $971, and ended last year at $422.82. Today’s jump marks the second big one-day move in the second half of this year alone.

Some investors have seized on the stock as beneficiaries of the growth associated with artificial intelligence and the belief that it can continue. The company said recent sources of demand have come largely from data centers and chip factory projects. This has attracted investors looking for different ways to capitalize on the spending boom.

It shows in the numbers. Comfort Systems (FIX) yesterday reported significant third-quarter year-over-year growth in revenue, net income and free cash flow, as well as greater backlog. This accumulation, which means continued strength in sales, is likely a big reason for the stock’s upward movement today.

“This was the second consecutive quarter in which the backlog expanded [by more than $1 billion] “sequentially, highlighting the strength of the demand backdrop,” UBS analysts, who have a bullish rating on the stock, wrote on Friday. Meanwhile, the stock’s valuation was already rich by some historical metrics before today’s jump, William Blair analysts wrote today, though they found that “justified” by the company’s performance.

The stock is not widely covered by Wall Street analysts, according to Visible Alpha, despite a market cap of $30 billion. But today’s action puts the current consensus price target, a few dollars below $920, in the rearview mirror.