Quanta vs. MasTec: Which AI Infrastructure Stock is the Better Buy?

The United States infrastructure contracting companies are benefiting from surging investment in power grids, renewable energy, telecom and AI data center buildouts. Market players like Quanta Services, Inc. PWR and MasTec, Inc. MTZ, that compete in utility and energy infrastructure markets, are banking on these long-term tailwinds.Quanta is a leading provider of electric power and utility infrastructure solutions, with a strong focus on transmission, distribution and large-scale energy projects. Meanwhile, MasTec engages in the engineering, building, installation, maintenance and upgrade of energy, communication, utility and other infrastructure.Let’s closely compare the fundamentals of the two infrastructure stocks to determine which one is a better investment now.The Case for Quanta StockQuanta’s mix across transmission and distribution, grid hardening, renewable integration and generation gives it multiple paths to participate as those plans become multi-year capital programs. Surging AI-related power demand and expanding utility investments are driving data center project opportunities, making data centers a central pillar of the company’s long-term growth strategy. PWR achieved a record total backlog of $48.5 billion as of March 31, 2026, providing a clear and durable runway for long-term growth. This record includes a 12-month backlog of $28.2 billion and remaining performance obligations of $26.2 billion. The Electric Power Infrastructure Services segment accounted for $40.1 billion of the total backlog.Besides, Quanta’s ability to self-perform 80-85% of its work keeps more of the execution under its control and can reduce reliance on subcontractors on large programs. It is heavily investing in deepening its vertical supply chain to offset the ongoing global uncertainties and rising inflation. The company expects to invest $500-$700 million over the next several years in power transformer manufacturing facilities and related strategy, which is intended to double transformer manufacturing capacity. Besides, it is also planning to nearly double off-site manufacturing, fabrication and logistics facilities to about 6.7 million square feet.At its March 2026 Investor Day, management outlined an opportunity to more than double adjusted EPS by 2030, with a 15-20% adjusted EPS growth target and a total addressable market estimate of $2.4 trillion through 2030, anchoring a longer-cycle demand backdrop for Quanta’s platform.Moreover, the company aims to sustain its integration discipline while continuing to layer in capabilities that fit its self-perform model. In the first quarter of 2026, acquired businesses contributed about $460 million of Electric revenues and about $335 million of Underground and Infrastructure revenues, supporting growth beyond organic end-market demand. Management continues to describe an active pipeline of strategic opportunities and a target leverage profile of 1.5-2x, which frames future tuck-in activity alongside organic investment.The Case for MasTec StockMasTec is also gaining from sustained demand across multiple infrastructure end markets. Communications growth is supported by rising data consumption, fiber deployment and multiyear broadband initiatives, including BEAD funding. Power Delivery demand is driven by grid modernization, system hardening and rising electricity needs, with data centers expected to materially increase power consumption. Clean Energy and Infrastructure is seeing growth across renewables, industrial projects and mission-critical facilities, including data centers. This diversification reduces reliance on any single market and supports more stable long-term growth.Backlog reached a record $20.3 billion in the first quarter of 2026, increasing approximately 7% sequentially and 28% year over year, supported by a 1.4x book-to-bill ratio. Management highlighted that backlog does not fully capture ongoing negotiations and verbal awards, indicating additional upside potential. Management highlighted growing opportunities in fiber interconnectivity, transmission infrastructure and turnkey data center construction, positioning MasTec at the center of several multiyear infrastructure trends.Owing to the robust market trends, MTZ raised its 2026 guidance, as it now expects revenues of approximately $17.5 billion (from $17 billion), adjusted EBITDA of $1.5 billion (from $1.45 billion) and EPS of $8.79 (from $8.40 per share), representing solid year-over-year growth across all metrics. This outlook reflects sustained demand, backlog conversion and improving operational execution, supporting continued earnings growth momentum.In the first quarter of 2026, adjusted EBITDA increased 73% year over year, with margin expansion of 170 basis points. Power Delivery and Pipeline segments showed notable margin improvements, supported by better execution and project performance. MTZ expects continued margin expansion across segments in 2026, with full-year EBITDA guidance raised to approximately $1.5 billion and margins improving modestly. This reflects a better project mix, pricing improvements and operational discipline.However, variability in project timing, dwindling cash flow, increasing inflation risks and global political unrest are proving to be near-term growth restrictions for the company. MasTec operates in markets influenced by government policy and regulatory approvals. Renewable energy investment remains tied to policy frameworks and potential changes to incentive structures could impact project activity in Clean Energy and Infrastructure. These factors introduce uncertainty into project pipelines despite favorable long-term demand trends.Stock Performance & ValuationAs witnessed from the chart below, in the year-to-date period, Quanta’s share price performance is below MasTec's but significantly above the broader Construction sector.Image Source: Zacks Investment ResearchConsidering valuation, over the last five years, Quanta has been trading above MasTec on a forward 12-month price-to-earnings (P/E) ratio basis.Image Source: Zacks Investment ResearchOverall, from these technical indicators, it can be deduced that PWR stock offers a slow growth trend but with a premium valuation, while MTZ stock offers a speeding growth trend with a discounted valuation.Comparing EPS Estimate Trends: PWR vs. MTZThe Zacks Consensus Estimate for PWR’s 2026 and 2027 earnings has trended upward in the past 30 days to $13.95 and $16.39 per share, respectively. The estimates for 2026 and 2027 imply year-over-year growth of 29.8% and 17.5%, respectively.EPS Trend of PWRImage Source: Zacks Investment ResearchThe Zacks Consensus Estimate for MTZ’s 2026 and 2027 earnings has trended upward in the past 30 days to $8.86 per share and $11.77 per share, respectively. The revised estimated figures for 2026 and 2027 imply 35.3% and 32.8% year-over-year growth, respectively.EPS Trend of MTZImage Source: Zacks Investment ResearchReturn on Equity (ROE) of PWR & MTZ StocksQuanta’s trailing 12-month ROE of 20.5% exceeds MasTec’s average, underscoring its efficiency in generating shareholder returns.Image Source: Zacks Investment ResearchShould You Invest in PWR Stock or MTZ Stock?Quanta and MasTec are both benefiting from the powerful multiyear infrastructure cycle tied to electrification, renewable energy, broadband expansion and AI-driven data center growth. However, the two companies currently present different investment profiles based on momentum, valuation and earnings visibility.Quanta, which currently sports a Zacks Rank #1 (Strong Buy), continues to stand out through its unmatched scale in electric transmission, grid modernization and utility infrastructure. Management’s target of 15-20% adjusted EPS growth through 2030 further reinforces confidence in Quanta’s durable growth runway. In addition, rising earnings estimates and stronger ROE reflect execution consistency and shareholder efficiency.MasTec, which currently carries a Zacks Rank #3 (Hold), is also executing well, supported by record backlog, improving margins and strong exposure to broadband, power delivery and renewable infrastructure. The company’s discounted valuation and stronger recent stock momentum may appeal to aggressive growth investors. However, variability in project timing, policy-sensitive renewable exposure and weaker cash-flow trends introduce higher near-term uncertainty.Thus, compared with MTZ stock, PWR stock’s superior backlog scale, operational control and stronger profitability metric make it the better stock to buy now for investors seeking a more balanced combination of growth, visibility and execution strength. You can see the complete list of today’s Zacks #1 Rank stocks here.7 Best Stocks for the Next 30 DaysJust released: Experts distill 7 elite stocks from the current list of 220 Zacks Rank #1 Strong Buys. They deem these tickers "Most Likely for Early Price Pops."Since 1988, the full list has beaten the market more than 2X over with an average gain of +23.9% per year. So be sure to give these hand picked 7 your immediate attention. See them now >>This article originally published on Zacks Investment Research (zacks.com).Zacks Investment ResearchWeiter zum vollständigen Artikel bei Zacks Weiter zum vollständigen Artikel bei Zacks