Why MasTec, Inc. (MTZ) Stock Fell 18.9% on Jul 31, 2026

Why did MTZ stock fall?

MasTec fell 18.9% on July 31, 2026, closing at $263.10 after a record second quarter — revenue up 23.4% to $4.37 billion, adjusted EBITDA up 39.8% to $384.2 million and an all-time-high 18-month backlog of $21.4 billion. The problem was the outlook, not the quarter. Although management raised full-year guidance against its own prior forecast, the new $18.2 billion revenue and $9.30 adjusted EPS targets still sat below published consensus of roughly $18.46 billion and $9.52, third-quarter adjusted EPS was guided to $2.98 against about $3.09, and roughly $400 million was removed from full-year Communications revenue. Much of the headline raise was attributable to the newly acquired Superior Group rather than to organic growth.

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  Raised guidance that was still below consensus: Full-year 2026 guidance moved up relative to MasTec's own prior outlook — revenue $18.2 billion, adjusted EBITDA $1.6 billion, adjusted diluted EPS $9.30 (up 42% year over year) and GAAP diluted EPS $6.20. But published consensus stood near $18.46 billion of revenue and $9.52 of adjusted EPS, so the raised outlook still landed short of what the Street was carrying.
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  A below-consensus third-quarter guide: Third-quarter adjusted diluted EPS was guided to $2.98 against roughly $3.09 consensus, on revenue of $4.93 billion and adjusted EBITDA of $482 million.
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  The raise leaned on the acquisition, not the base business: Superior was expected to contribute roughly $800–900 million of 2026 revenue and $0.50–$0.65 of adjusted EPS after closing, while management removed about $400 million from Communications revenue. Stripping out the acquired contribution leaves a materially weaker organic bridge than the headline raise implies.
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  Communications margins went backwards: Communications was the clear weak spot: second-quarter revenue rose just 6.2% to $888.9 million while segment EBITDA fell 11.6% to $73.1 million and margin dropped 170 basis points to 8.2%. Segment backlog also slipped sequentially, to $5.46 billion from $5.50 billion. Management expected second-half Communications margins to improve roughly 200 basis points from first-half levels, but guided full-year margins to remain in the high single digits — about 100 basis points below both the prior year and prior expectations.
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  A steep same-day target cut: JPMorgan cut its price target to $369 from $549 on July 31. Further cuts followed on August 3 from Citigroup ($408 from $483), KeyBanc ($371 from $500), Baird ($363 from $475) and TD Cowen ($420 from $470).

How the story developed

• April-July 2026The shares de-rated roughly 37% over three months, falling from about $429 in late June to $287 by July 29.
• July 20, 2026MasTec closed its acquisition of The Superior Group, a North American electrical contractor with about 3,000 employees, in a cash-and-stock transaction valued at roughly $1.65 billion plus a potential earnout.
• July 30, 2026The stock rallied 12.9% to $324.44 during the session; second-quarter results were released after the close at 4:19pm ET.
• July 31, 2026Management hosted the earnings call at 9:00am ET. Shares opened at $277.00 and closed at $263.10, down 18.9% on 3.9 million shares. JPMorgan cut its target to $369 from $549.
• August 3, 2026Citigroup, KeyBanc, Baird and TD Cowen all cut price targets, though every one of them remained well above the traded price.

What it could mean for MTZ investors

Initial detection

BestStocks first flagged MTZ intraday on Jul 31, 2026; this analysis was finalized after the close using the confirmed −18.9% session move and additional catalyst research.

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