As we approach the halfway point for 2012, now's a good time to look back at what's happening with the stocks that interest you. By making sure you know the important things that a company accomplished -- as well as the setbacks it experienced -- you can make a better decision about whether it's a smart investment for your portfolio.

Today, let's take a look at Manitowoc (NYSE: MTW). The company has an unusual mix of businesses, as it builds cranes for construction projects as well as provides food-service machinery for restaurants and other food-business customers. As its volatile share price reveals, Manitowoc is very sensitive to expectations about economy growth. Let's take a quick look at how the stock is doing so far this year.

Stats on Manitowoc

2012 YTD Return 14%
Market Capitalization $1.39 billion
Revenue, Most Recent Quarter $860 million
Year-Over-Year Revenue Growth, Most Recent Quarter 17.5%
Net Income, Most Recent Quarter $0.1 million
CAPS Rating ****

Source: S&P Capital IQ.

What's behind Manitowoc's moves?
 Manitowoc had a pretty lousy 2011, as its emerging-market exposure failed to offset a slow U.S. construction industry. But the company started 2012 on a high note, as shares soared more than 50% on hopes that a full-fledged economic recovery in the U.S. would be accompanied by continuing strength in China and other higher-growth emerging economies. That same thesis helped push construction-equipment makers Caterpillar (NYSE: CAT) and Terex (NYSE: TEX) up sharply to start 2012 as well.

But in the past several months, Manitowoc has given back a big share of its gains from earlier in the year. Worries about the global economy are the primary culprit, as a surprise Chinese interest rate cut signaled that growth prospects there may be weaker than many thought. Manitowoc also has more exposure to Europe than many of its peers, raising particular concerns about the sovereign debt crisis there. At the same time, Manitowoc has too much debt to be able to move nimbly to take advantage of new opportunities where they arise, which could cost it in China as both Caterpillar and mining-equipment maker Joy Global (NYSE: JOY) have been able to capitalize on some big projects there.

Even with its most recent quarterly revenue growth, Manitowoc missed expectations. Yet the company has gotten strong reviews from food-service customer McDonald's (NYSE: MCD) for its blend-in-cup ice dispenser machines, and as its food customers push into new markets, they take Manitowoc with them.

Changing economic prospects are the big reason for Manitowoc's back and forth share price in 2012. If you'd prefer some other stock ideas with better track records of success, let me invite you to learn about three smart long-term stock plays in the Fool's latest special report. It's yours for the taking and is absolutely free, but don't miss out -- click here and read it today.

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