Comfort Systems is One of the S&P 500’s Top Performers in 2026

Core Insights - Comfort Systems USA Inc. has experienced a remarkable 43% increase year-to-date through February 11, 2026, reaching a stock price of $1,335.14, driven by demand from data center buildouts and a shift towards AI infrastructure [2] - The company has seen a 208% increase in shares over the past year, raising questions about the sustainability of this rally given its current trading at 54 times trailing earnings [2] Financial Performance - The momentum in Comfort Systems' stock is attributed to its Q3 2025 results, which reported revenue of $2.45 billion, exceeding Wall Street's estimate of $2.18 billion by 12% [3] - Earnings per share (EPS) for Q3 2025 were $8.25, surpassing the consensus estimate of $6.29 by 31%, and doubling year-over-year results [3] - Operating cash flow increased by 83% to $553.3 million, and the company's backlog reached a record $9.38 billion, with $1 billion in same-store growth [4] Institutional Interest - Inclusion in the S&P 500 has led to significant institutional buying, with firms like WCM Investment Management and New York State Common Retirement Fund increasing their stakes [5] - Institutional ownership stands at 96.51%, indicating that the stock's rise is driven by institutional investors rather than retail speculation [5] Analyst Ratings - Analysts have shown strong support, with UBS raising its price target from $1,140 to $1,310, citing a strong backlog and labor shortages that enhance pricing power [6] - Stifel has increased its target to $1,196, while the Wall Street consensus price target is $1,247, with six Buy ratings and two Holds [6] Valuation Concerns - The stock is currently trading at 42 times forward earnings and has a PEG ratio of 2.06, reflecting expectations of substantial growth [7] - Insider selling has raised concerns, with CFO William George selling 9,649 shares for approximately $7.3 million and CEO Brian Lane selling 7,158 shares worth $6.8 million, with no insider buying reported in the past three months [7]