Comfort Systems vs. Quanta: Which Infrastructure Stock to Buy Now?

By Sraddha Singha | January 19, 2026, 1:10 PM

The declining Fed interest rates and a favorable public spending environment are boding well for the infrastructure companies of the United States, including names like Comfort Systems USA FIX and Quanta Services, Inc. PWR. The booming trends toward AI-related products and services are primarily driving the growth prospects of such firms in the economy.

On Dec. 10, 2025, the Federal Reserve slashed its interest rates by another 0.25 percentage points, setting the benchmark between 3.5% and 3.75%. The reduction in the borrowing rate catalyzes the ongoing favorable market trends, boosting more project initiations, leading to a promising future.

Comfort Systems offers installation and contracting services across the HVAC market and is currently focused on seeking opportunities for large-scale projects and investing additional capital in inorganic growth initiatives. Conversely, Quanta’s business surrounds large-scale electrical and utility infrastructure projects, with its focus mainly concentrated on margin improvement efforts and the self-perform model.

Let’s dive deep and closely compare the fundamentals of the two stocks to determine which one is a better investment now.

The Case for Comfort Systems Stock

Comfort Systems is realizing benefits from the robust demand trends across the Technology sector, mainly because of strong data center and chip manufacturing-related activities. So far in 2025, the Technology sector contributed 42% of the total revenues, reflecting growth from 32% a year ago, thanks to hyperscalers and related infrastructure developers continuing to invest aggressively, despite ongoing macro headwinds. As of Sept. 30, 2025, the company had a record backlog of $9.38 billion, with a same-store backlog of $9.2 billion, indicating year-over-year increases of 65.1% and 62%, respectively.

FIX is benefiting from customers committing earlier and booking projects further out, with meaningful portions of the backlog now extending into 2026 and 2027. Beyond data centers, industrial and institutional markets remain supportive. Industrial customers represent roughly two-thirds of revenues, while institutional verticals such as healthcare, education and government continue to show steady activity, including new hospital builds and expansions.

The company also ensures its shareholders are satisfied through share repurchases and dividend payments. During the first nine months of 2025, it repurchased 0.3 million shares for approximately $125.4 million under the buyback program. Also, on Oct. 23, 2025, Comfort Systems’ board of directors hiked the quarterly dividend payment by 20% to 60 cents per share ($2.40 per share annually).

However, FIX’s growing exposure to hyperscale data centers is a double-edged sword. Any slowdown in AI-driven capital expenditures, project deferrals by cloud providers, or power availability constraints could compress backlog growth and utilization. Besides, project delays, scope changes, customer funding issues or cancellations, particularly in large and complex projects, could result in backlog conversion failure. Comfort Systems is also concerned about shortages of skilled labor and rising wage pressure in the current market dynamics. Besides, exposure to competitive pricing, project mix shifts and normalization from peak conditions could disturb its current margin levels and reduce profitability.

The Case for Quanta Stock

Being a specialty contracting services provider, Quanta is capitalizing on the booming trends surrounding electric transmission, grid modernization and power generation tied to AI, data centers, electrification and reshoring. The management indicated that accelerating demand in the Electric segment and broad activity across key end markets are reinforcing these trends and strengthening overall project momentum. As of the third quarter of 2025, PWR’s backlog reached a record $39.2 billion, up from $33.96 billion a year ago, underscoring robust demand visibility.

Moreover, disciplined bidding, effective risk management and a favorable project mix are primarily driving PWR’s margin expansion and consistency. Unlike many peers, Quanta self-performs 80–85% of its work. This approach provides greater control over costs, schedules and quality, mitigating risks associated with subcontracting. In the first nine months of 2025, operating margin increased to 5.5% from 5.2% on a year-over-year basis. During the same time frame, gross margin expanded 50 basis points year over year to 14.8%.

Quanta consistently focuses on reducing leverage while maintaining capacity for selective acquisitions, organic investment and shareholder returns. During the first nine months of 2025, PWR repurchased 538,559 shares for $134.6 million, with $365.1 million remaining under its buyback program. The balance between reinvestment and shareholder returns demonstrates disciplined capital management, enhancing long-term value creation. For 2025, the company expects free cash flow of $1.3-$1.7 billion. It had reported $1.55 billion in 2024.

Although demand visibility is strong, execution risk remains elevated due to the increasing size and complexity of infrastructure projects. Large transmission, generation and data center-related programs often face permitting delays, interconnection bottlenecks and regulatory approvals that can push Quanta’s revenue recognition to the south. Additionally, while renewable and battery projects remain active, the pace of growth is moderating compared with prior years, creating variability in quarterly mix.

Stock Performance & Valuation

As witnessed from the chart below, in the past six months, Comfort Systems’ share price performance stands significantly above Quanta and the broader Construction sector.