The trouble with investing in cyclical stocks is that once they've had a good run, you run the risk of considerable volatility as some weaker hands try to pick the top of the cycle and bail out. That would seem to be the case today with engineering and construction firm Fluor (NYSE:FLR) -- the fourth-quarter results weren't that bad, and the future is still pretty interesting.

Speaking of the quarter, revenues were up 44%, though segment operating profits fell 10%. And while reported net income rose 36%, new project awards and the backlog grew only 1%. Results were similarly mixed on a segment basis -- revenue growth was strong across the board, but margins fell in global services and oil/gas, and the industrial/infrastructure unit posted a loss because of some large charges from transportation and hotel projects.

Here's the thing, though; I don't think we're even close to the end of the upswing in some of Fluor's major markets. Investments in energy and petrochemical projects usually lag upswings in oil/gas prices, and so there could still be more room to run here. Furthermore, the power industry is just starting to get up off the mat. There are at least 130 proposed new coal plant projects, and Fluor stands to get at least some of them -- projects like the recently announced plant that Fluor will build for Newmont Mining (NYSE:NEM), as well as a project underway for Peabody Energy (NYSE:BTU).

And what about other sorts of projects? Why can't Fluor get a piece of all these new ethanol plants slated to go up around the country? And let's not forget other newer ideas like coal liquefaction and coal gasification. Fluor already has an alliance with ConocoPhillips (NYSE:COP) for coal gasification, and that technology is finally getting some attention on a global basis.

Certainly Fluor isn't alone here. There are other major engineering/construction companies that are seeing a lot of the same favorable trends. And by all means, Fools should consider rivals like Foster Wheeler (NASDAQ:FWLT), Washington Group (NASDAQ:WGII), and Shaw Group (NYSE:SGR) in the process of doing their due diligence.

At the bottom line, this is a stock that can flummox you. Valuation doesn't look like any great bargain, but it's tough to ignore all of that potential new business still out there. Tread carefully, fellow Fools, but don't write this one off just yet.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).