Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of industrial machinery manufacturer Terex (NYSE: TEX) were flattened by the market today, as if run over by one of the company's own asphalt rollers. The stock fell as much as 11% on very heavy trading volume.

So what: In the just-reported second quarter, Terex booked non-GAAP earnings of $0.10 per share on $1.5 billion in revenue -- both tremendous improvements over the year-ago quarter, but also far short of Wall Street estimates. The company got blindsided on multiple fronts, including slow road-building activity in Brazil, a weaker market than expected for cranes in Europe, and skinny margins in the aerial platforms division.

Now what: Management raised its sales guidance for the full year to the top of the previous range, but also lowered its earnings target. That's bad news for Terex's margins, and provides plenty of fodder for today's drastic plunge. Rival Manitowoc (NYSE: MTW) felt some of Terex's pain, while equipment giants Deere (NYSE: DE) and Caterpillar (NYSE: CAT) plowed on toward tomorrow's report from the big Cat, unperturbed.

Interested in more info on Terex? Add it to your watchlist.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool is investors writing for investors.