One step down the chain from the giants — where the cheques land

The Data Centre Boom is our master theme, and its money flows downhill: the giants announce the capital budgets, developers pour the shells — and these three companies do the work that makes a building a data centre: the switchgear and wiring, the cooling and mechanical plant, the network fit-out. A contractor’s whole future is its order book — the signed work not yet done. The books below have grown 70% to 153% since late 2024, and the filings say why in plain words: EMCOR credits “several data center construction contracts”; Comfort Systems’ Technology customers grew from $386M to $4.1B of revenue in four years.

Now the honest half, and it is this chapter’s whole risk lesson. Our toolmakers page shows companies with a cushion when building slows — service revenue on installed machines. A construction contractor has no such rent. Its cushion is the book itself — and the book is a countdown, not an annuity. Comfort Systems expects 65–75% of its book to turn into revenue within twelve months; work billed is work gone. As long as new signings outrun the billing, the book grows and the future thickens. The quarter signings stop, the book starts counting down in plain sight — which is why the one chart this page keeps is the books themselves.

None of this is a forecast — the watch list in Part four is how a reader spots the turn. GARPify covers all three with full company reports — EME FIX IESC — built from the companies’ own filings and our standard data pull, every claim checked against its source, and no advice anywhere.

Three contractors, three ways to ride one boom

Same boom, three different builds: the industrial-scale veteran, the mid-size firm whose customer table became a technology story, and a founder-controlled small-cap wiring the internet’s biggest names. One summer touched all three — each sits about a fifth below its 52-week high with its book at a record.

Three tags, one calm outlier

A price-earnings tag only means something against that company’s own history. All three pulled back about a fifth from their highs this summer — and unlike most of the AI complex, one of them now trades close to its own five-year normal:

What the shelf says together: the market is charging 1.1 to 1.4 times each company’s usual rate after a 21–22% pullback — a far milder markup than the toolmakers wear. The catch is in the earnings under the tags: two of the three roughly doubled their earnings in a year. A modest-looking tag on boom-level earnings is only modest while the boom holds. Each report prices its own company against its own history and hands the reader the choice; none of them tells you what to pay.

Four dials, all published quarterly

The giants’ cheques. These books are downstream of the capital budgets of Meta, Microsoft, Amazon and Alphabet — the companies of our giants coverage. The quarter the giants’ capex guidance flattens is the quarter to re-read this page; it reaches the books here two steps later.

The books’ refill. Every quarter each company prints its book. The level matters less than the direction: a book that stops growing while billing continues is a countdown clock. This is the chart’s standing job above.

The margin on the work. Contractors bid much of their work at fixed prices; a boom is when bidding discipline is easiest to lose. Each report reads its company’s operating margin against its own history — rising margins on a rising book is the healthy pattern; either one breaking ranks is news.

The tags themselves. All three report within a month of each other this autumn — Comfort Systems October 22, EMCOR October 29, IES November 20 (dates vendor-estimated) — and each report scores its company the day the filings land.

There is no clean fund for this shelf

Unlike the chip toolmakers, this basket has no fund that holds it cleanly. The closest vehicle is broad US-infrastructure funds — the largest, PAVE (Global X US Infrastructure Development, fee 0.47%), holds EMCOR at about 2% of a 101-name portfolio, and holds neither Comfort Systems nor IES at all (checked against its published holdings, September 2026). Broad index funds carry the two larger names at small weights inside hundreds of stocks. If this theme convinces you, the individual names — through your own research or your advisor — are the only clean expression, and that is precisely what the three company reports are for: EME FIX IESC

What the stock charts say — our standard trend test

One test, one definition, every page: weekly closes against the 52-week rolling average, with the average’s direction over the last 14 weeks.