As investors in a jittery market leap out of quality stocks with cat-like reflexes, savvy Fools often jump, too … but in the opposite direction.

The beating that Terex (NYSE:TEX) shares took on Thursday strikes this Fool as just such an opportunity. Terex had cut its 2008 earnings outlook by about 7% to between $6.35 and $6.65 per share and cut net sales estimates by 3%.

The basis for the revision is hardly an earth-shattering revelation: Demand for aerial work platforms and construction equipment is down in the U.S. and Western Europe, and manufacturing costs in those segments have risen substantially. Anyone who didn't see weakness coming from construction in these regions needed a wake-up call anyway. Thanks to analysts and some jumpy investors, this wake-up call came complete with alarms and whistles. After holding up fairly well Wednesday in the face of Joy Global's (NASDAQ:JOYG) poorly received earnings, Terex shares lost nearly 20% on Thursday.

While Terex may experience softening demand, keep in mind that overall demand for its products is still very strong. The company reported a $4.2 billion sales backlog in July, which was up 50% from the start of the year. According to Terex CEO Ron DeFeo, both the cranes and the materials processing and mining segments are continuing to outperform even the company's internal projections.

With the Dow retreating sharply and concerns for the financial markets mounting still, it's becoming difficult to find investors taking a longer-term view. Meanwhile, some companies are taking major long-term gambles that global commodity demand will remain strong: Terex recently acquired Italian port equipment manufacturer Fantuzzi, Caterpillar (NYSE:CAT) is investing $1 billion for international growth, Diana Shipping (NYSE:DSX) and other dry-bulk competitors are building ships as fast as they can, and even steelmaker POSCO (NYSE:PKX) wants to dive into the shipbuilding business.

Despite the weakness in two of the company's businesses, I view Terex shares as severely undervalued after now. Forward-looking Fools should give this one a good look.

Further Foolishness:

Fool contributor Christopher Barker captains yachts and writes about stocks. He can also be found blogging actively and acting Foolishly in the CAPS community under the username TMFSinchiruna. He owns shares of Diana Shipping and Caterpillar. POSCO is a Motley Fool Income Investor pick. The Fool owns shares of Terex. The Motley Fool has a disclosure policy.