What smart money is saying about Comfort Systems USA, Inc.
FIX · Industrials · Engineering & Construction · Market cap $40.86B
7 funds in our archive have pitched Comfort Systems USA, Inc., most recently Argent Mid Cap Strategy in September 2026.
Company profile
Comfort Systems USA, Inc., together with its subsidiaries, provides mechanical and electrical installation, renovation, maintenance, repair, and replacement services for the mechanical and electrical services industry in the United States. The company operates through two segments: Mechanical and Electrical. It offers heating, ventilation, and air conditioning systems, as well as plumbing, electrical, piping and controls, off-site construction, monitoring, and fire protection. The company is also involved in the design, engineering, integration, installation, and start-up of mechanical, electrical, and plumbing (MEP) and related systems in new buildings; and renovation, expansion, maintenance, monitoring, repair, and replacement of systems in existing buildings. In addition, it provides remote monitoring of power usage, temperature, pressure, humidity and air flow for MEP and other building systems. The company serves building owners and developers, general contractors, architects, consulting engineers, and property managers in the commercial, industrial, and institutional markets. Comfort Systems USA, Inc. was founded in 1917 and is headquartered in Houston, Texas.
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Fund signal · last 12 months
20 lettersFunds are split between buying and selling
+1
Net flow
5 buys · 3 new positions · 56%4 sells · 2 full exits
Moves described in fund letters in our archive. A sentence published word for word by several funds of one house in the same quarter counts once.
Position history
Between Q1 2025 and Q3 2026, 21 fund letters reported a position in Comfort Systems USA, Inc., with 6 buys (opened or added) and 4 sells (trimmed or exited).
| Quarter | Letters | Bought | Sold | Theses |
|---|---|---|---|---|
| Q3 2026 | 8 | 2 | 2 | 3 |
| Q2 2026 | 8 | 3 | 2 | 0 |
| Q1 2026 | 4 | 0 | 0 | 0 |
| Q4 2025 | 0 | 0 | 0 | 1 |
| Q2 2025 | 1 | 1 | 0 | 2 |
| Q1 2025 | 0 | 0 | 0 | 1 |
Bought and Sold count moves: the same sentence published by several funds of one house in a quarter counts once.
Fund activity · 21 positions · 10 moves
- September 2026
“Comfort Systems USA, Inc. (FIX) grew revenue 50% and lifted its backlog by more than 70% yet traded lower alongside other data-center builders.”
Comfort Systems USA, Inc. - September 2026
“Comfort Systems USA, Inc. Specialty mechanical, electrical, & plumbing systems contractor for high-performance industrial & commercial buildings, which include datacenters, semiconductor fabs, & pharmaceutical manufacturing sites 2.71”
Comfort Systems USA, Inc. - September 2026
“Four new positions were added to the strategy in the quarter. Block (XYZ) operates two financial platforms: Square helps businesses accept payments and manage finances and Cash App works as a digital wallet for consumers. Demand for XYZ's lending products is growing sales across both platforms, and an aggressive restructuring program is cutting costs. The combination is lifting XYZ's profit outlook higher. Comfort Systems (FIX) builds and installs mechanical, electrical and plumbing systems inside large commercial facilities.”
Comfort Systems USA, Inc. - TrimmedArgent Mid Cap StrategySeptember 2026
“Within AI infrastructure, we trimmed Hewlett Packard Enterprise, Comfort Systems and Vertiv.”
Comfort Systems USA, Inc. - September 2026
“A second group of reductions addressed concentration in AI infrastructure, which Vertiv's sale also served. We sold Fabrinet, a precision optical and electronic manufacturing services provider to hyperscalers, networking companies and telecommunications customers. Demand for data center interconnect, high- performance computing and next generation optics remains strong, but the risk and reward had become 5 SMID Cap Quarterly Commentary 2026 Third Quarter less favorable as the portfolio's overall exposure grew. Company specific considerations reinforced the decision, including competitive pressure and share loss in parts of its Datacom business, significant customer concentration, the potential for AI infrastructure spending to become more cyclical after a period of rapid expansion, and a more capital-intensive phase in which heavy investment in new manufacturing capacity has sharply lowered free cash flow despite continued revenue growth. We trimmed Monolithic Power Systems, a leading provider of power management semiconductors, whose Enterprise Data revenue grew more than 160% year over year in the most recent quarter and is becoming a much larger part of the business, which also made its company-specific risk and reward less favorable. We also trimmed Comfort Systems, a provider of mechanical, electrical, plumbing and building automation services with significant participation in data center construction.”
Comfort Systems USA, Inc. - September 2026
Listed in Buffalo funds Mid Cap Growth Fund’s reported holdings.
Comfort Systems USA, Inc. - September 2026
Listed in Buffalo funds Mid Cap Discovery Fund’s reported holdings.
Comfort Systems USA, Inc. - New positionLiontrust GF Global Dividend FundSeptember 2026
“NRG Energy (-20%), bought after its shares fell on second quarter results, fell further after purchase and cost 0.4 points, and Caterpillar (-24%) fell despite the record quarter described above (-0.3). Fortescue (-12%), Comfort Systems (-10%), newly added, Ciena (-10%) and Rio Tinto (-7%) also detracted; our Chinese holdings cost 1.5 points in aggregate through the country lens. Outside the portfolio, the Fund's underweight to Microsoft (not held) was the largest single drag on relative return, costing 0.9 points as the shares rose 38% on an acceleration in Azure cloud revenue growth. Our preferred cloud exposure among the hyperscalers remains those with full stack economics, Amazon, Alphabet and Meta, rather than Microsoft, whose significant software estate we believe AI agents are disintermediating. Portfolio activity This was a highly active quarter: 13 stocks exited, replaced with 13 new names from our watchlist, and our weighting to information technology, which we had cut to c.25% of the Fund by the end of June (underweight relative to the benchmark), was rebuilt to c.39% by the end of the period. We would not expect this level of activity to be typical, and we are not seeking turnover for its own sake: when the market offers world class franchises back at material discounts to where you sold them weeks earlier, while their earnings power strengthens, sitting still is the greater risk. Three months ago we wrote that we had sold eight winners while they were still winning, recycling the capital into wider valuation gaps. July then reopened gaps in several of the companies we had sold: they fell sharply while their earnings kept rising, and we bought them again. SK hynix and Ibiden are described above; Applied Materials, the semiconductor equipment leader, and GE Vernova returned as valuations fell back to attractive levels; and Rio Tinto, whose strong copper delivery (EBITDA up 84% to $5.7 billion in the first half) supported a 43% increase in the interim dividend, rejoined the Fund. The July sell-off also gave us our first opportunity in years to own ASML, the sole supplier of the lithography on which every leading edge chip depends, which has long traded at prices we could rarely justify. We also made a number of new additions. Intel has struggled in recent years but has been transformed under chief executive Lip-Bu Tan: 15 of its 18 most senior managers have changed under his watch, the company told us in Silicon Valley in September. We are increasingly confident Intel is well placed for the agentic era, in which the work around every accelerator runs on CPUs, and the second quarter results showed it: revenue rose 25% year-on-year to $16.1 billion, its fastest growth in more than fifteen years, and its data centre and AI division grew 59%. Delta Electronics, whose power supplies and cooling systems go into AI data centres, was added after its shares had fallen c.40% from their May peak. NRG Energy, the Texas power producer, was bought after its shares fell on second quarter results, because its next leg of growth is contracted: a 1.2GW gas plant for a hyperscaler on a contract of at least 15 years, with c.95% of the plant's free cash flow from availability payments. NRG has raised its dividend by 8% in each of the last six years, and contracted demand of this kind should sustain that growth. We also added ABB, the Swiss electrification and automation leader, and Comfort Systems, the US mechanical and electrical contractor building data centres.”
Comfort Systems USA, Inc. - June 2026
“In industrials, Comfort Systems benefited from demand for complex mechanical, electrical and modular construction capabilities tied to data center and manufacturing buildouts. We profitably exited the name during the quarter.”
Comfort Systems USA, Inc. - June 2026
“Among our top contributors in Q2 were Twist Bioscience, Lattice Semiconductor and Comfort Systems. Twist Bioscience is a life sciences company that leverages a proprietary silicon-based DNA writing platform, with synthetic biology applications across drug discovery, diagnostics, agriculture and industrial materials. Recent results exceeded expectations, driven by strength in its DNA synthesis and protein solutions segment, as well as improving growth in next- generation sequencing. The company continues to benefit from growing demand from large pharmaceutical and AI customers for DNA synthesis and data generation, which may support incremental growth as computational approaches to drug discovery gain broader adoption. We trimmed the position during the quarter due to the stock’s recent strong performance. Lattice is a fabless leader in low-power field-programmable gate arrays. The company reported strong quarterly results, with revenue and guidance exceeding expectations as demand accelerated across servers, communications and industrial applications. The company also announced plans to acquire AMI, a complementary firmware and infrastructure management platform expected to expand Lattice’s data center capabilities and broaden its addressable market. We added to the position during the quarter. Comfort Systems is a provider of heating, ventilation and air conditioning services. Strong demand from data center construction, driven by hyperscaler customers, now accounts for a majority of its revenue. Recent earnings results exceeded expectations, with year-over-year same-store revenue growth of 51% and margin expansion. It also raised full-year guidance. We view the company as well positioned to benefit from ongoing investment in data center infrastructure and added to the position during the quarter.”
Comfort Systems USA, Inc. - HoldsAve Maria FundsJune 2026
“Comfort Systems USA, Inc. provides mechanical and electrical contracting services.”
Comfort Systems USA, Inc. - June 2026
“Comfort Systems USA, Inc. 2.00”
Comfort Systems USA, Inc. - June 2026
“As noted above, Direct AI beneficiaries and a few other stocks in the portfolio rose sharply and in a number of instances prices raced ahead of fundamentals compressing future expected returns. We exited several positions including Credo Technology (CRDO), Semtech (SMTC), Nova Limited (NVMI), Universal Technical Institute (UTI) and Comfort Systems (FIX), entirely, and trimmed others, such as Modine (MOD), Forgent Power Solutions (FPS), Onto Innovation (ONTO), TTM Technologies (TTMI), and Carpenter Technology Corp (CRS).”
Comfort Systems USA, Inc. - June 2026
“Comfort Systems (FIX) and Quanta Services (PWR) once again taking top spots among the portfolio’s best performers.”
Comfort Systems USA, Inc. - June 2026
“The top contributors to performance for the quarter were Comfort Systems and Sterling Infrastructure in Infrastructure Area of Interest (AoI); Quanta Services (Power Generation); and Coherent (Connectivity).”
Comfort Systems USA, Inc. - New positionParnassus Investments Growth Equity FundJune 2026
“We continue to maintain a portfolio balanced between offense and defense. We have taken advantage of ongoing market volatility to selectively participate in secular trends at attractive valuations in AI beneficiaries including hyperscalers, semiconductors and data center and energy infrastructure. Due to the market concentration in mega-cap technology companies, the portfolio’s largest absolute weight continues to be the Information Technology sector, where we have an underweight position relative to the Russell 1000 Growth Index. The portfolio’s largest active weights relative to the Russell 1000 Growth are in Health Care, Communication Services and Materials. The portfolio has no exposure to Energy or Real Estate. We made several position changes during the quarter, selling six positions and adding five new ones. We also adjusted several position sizes in response to the Russell 1000 Growth Index reconstitution. In the Health Care sector, we see compelling long-term idiosyncratic growth opportunities in drug discovery, diagnostics and medical innovation. During the quarter, we added Twist Bioscience, a biotechnology company with a proprietary silicon-based DNA synthesis platform, and Revolution Medicines, developer of a promising new drug for pancreatic cancer. Other positions added during the quarter included Sandisk, a leader in flash memory solutions; Comfort Systems, a mechanical, electrical and plumbing contractor, which provides key labor for AI infrastructure build-out; and Lumentum, which makes optical products used in AI data center networking.”
Comfort Systems USA, Inc. - March 2026
“OUTLOOK BUFFALO MID CAP DISCOVERY FUND March 31, 2026 TOP CONTRIBUTORS (CONITINUED) Comfort Systems USA (FIX) was another top contributor with shares rising 48%.”
Comfort Systems USA, Inc. - March 2026
“ Comfort Systems (FIX) rose after reporting a material earnings beat in February, supported by strong backlog growth and continued margin expansion.”
Comfort Systems USA, Inc. - March 2026
“• Comfort Systems USA is a leading national mechanical and electrical contractor that installs, maintains, and services HVAC, plumbing, piping, and electrical systems for commercial, industrial, and institutional buildings. The company has emerged as a critical infrastructure partner in the data center buildout, where its specialized mechanical and electrical capabilities are in high demand as hyperscalers expand capacity at an accelerating pace. During the quarter, shares contributed positively to performance after the company delivered better-than-expected fiscal fourth-quarter results, highlighted by strong revenue growth, record margins, and a backlog that nearly doubled year over year.”
Comfort Systems USA, Inc. - March 2026
“• Comfort Systems USA is a leading national mechanical and electrical contractor that installs, maintains, and services HVAC, plumbing, piping, and electrical systems for commercial, industrial, and institutional buildings. The company has emerged as a critical infrastructure partner in the data center buildout, where its specialized mechanical and electrical capabilities are in high demand as hyperscalers expand capacity at an accelerating pace. During the quarter, shares contributed positively to performance after the company delivered better-than-expected fiscal fourth-quarter results, highlighted by strong revenue growth, record margins, and a backlog that nearly doubled year over year.”
Comfort Systems USA, Inc. - New positionBrown Advisory US Mid Cap Growth FundJune 2025
“ Comfort Systems is one of the largest non-union MEP (mechanical, electrical, plumbing) contracting firms in the U.S.”
Comfort Systems USA, Inc.
Also mentioned · 1
These funds discuss Comfort Systems USA, Inc. as a competitor, benchmark or comparable, without disclosing a position in it.
- June 2026
“The strategy’s top contributors included several AI-related holdings, including Bloom Energy (BE), Jabil (JBL), Lattice Semiconductor (LSCC), and Comfort Systems (FIX).”
Comfort Systems USA, Inc.
Fund coverage · 7 theses
- Argent Mid Cap StrategySeptember 2026
Comfort Systems benefits from data center and mission-critical infrastructure spending, but the stock moved on valuation compression despite strong execution.
Read the full thesis Comfort Systems provides modular mechanical, electrical, and plumbing construction for data centers and semiconductor plants, driving growth and margin expansion.
Read the full thesis- Argent Capital Management SMID Cap StrategySeptember 2026
Comfort Systems provides MEP and building automation services with solid fundamentals and strong data center demand, though valuation had become rich.
Read the full thesis - Aristotle Large Cap GrowthDecember 2025
Comfort Systems USA is a leading mechanical and electrical contractor with recurring revenues and CHIPS/IRA-driven exposure that justify a premium valuation.
Read the full thesis Comfort Systems is a leading provider of MEP building systems in the US, poised for continued growth driven by strong construction demand and a skilled labor shortage, while maintaining a focus on profitability, employee retention, and successful acquisitions.
Read the full thesisComfort Systems is a leading non-union MEP contracting firm in the U.S. that is poised for growth and higher margins due to a skilled labor shortage and strong demand in construction.
Read the full thesis- Polen US Smid Company GrowthMarch 2025
Comfort Systems is a leading mechanical, electrical, and plumbing provider with a strong track record in new construction and a mid-teens earnings growth outlook, primarily focused on commercial and industrial markets.
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