Most investors don't keep tabs on their companies' fundamental value. That's a mistake. If you take the time to read past the headlines and crack a filing now and then, you're in a much better position to spot potential trouble early. Better yet, you'll improve your odds of finding the underappreciated home run stocks that provide the market's best returns.

We can help you keep tabs on your companies with, our free, personalized stock-tracking service. Here are five stocks from my watchlist that have been hot lately.

1. Clean Energy Fuels (Nasdaq: CLNE)
Clean Energy Fuels attracted my notice after rising roughly 22% in the past month. The company is building out a network of natural gas stations, and it got a boost after President Obama's speech on the nation's energy problems included praise for natural gas. The company has been benefitting from LNG stations at Pilot Flying J stations. While the stock is expensive, it could be a long-term winner, should rising gas prices prompt more truckers to switch to alternative fuels. 

2. Molycorp (NYSE: MCP)
Molycorp caught my eye after increasing 53% the past month. Molycorp is the largest of the U.S. rare-earth miners, and it's risen steadily as the company announces further acquisitions. As fellow fool Sean Williams pointed out, the company is priced for perfection at almost 13 times book value and 160 times trailing annual sales. The Fool's investing community, CAPS, is also down on Molycorp, giving it and fellow rare-earth mineral company Rare Element Resources (AMEX: REE) one-star ratings. No matter what the stock price does, Molycorp should prove interesting to watch the next few years.  

3. CAMAC Energy (AMEX: CAK)
CAMAC Energy has been on a tear recently. Its stock has risen 25% the past month, although it has actually lost ground since the beginning of the year. Like HyperDynamics (AMEX: HDY), this energy producer is focused on the west coast of Africa. If things work out, it could be a huge winner. CAMAC recently announced the results of an independent study which showed that its reserves were much higher than previously estimated. If the company can overcome very real challenges to successfully move into full production of its fields, this stock could take off. For what it's worth, the company does not have much debt, but it has been very liberal in issuing shares. Hopefully, this one pays off for investors.

4. Yanzhou Coal Mining (NYSE: YZC)
Yanzhou Coal Mining caught my eye after rallying 19% over the past month. Like fellow Chinese coal producer L&L Energy (Nasdaq: LLEN), Yanzhou has been riding rising coal prices in China, as the country continues to add new coal power plants to power its booming economy. If this trend continues as expected, Fool metals expert Chris Barker believes coal supplies will remain tight for the foreseeable future.

5. Precision Drilling (NYSE: PDS)
Precision Drilling drew my attention after rising 21% the past month. The stock has done even better over the past six months, crushing the averages by nearly doubling. Precision Drilling is a Canadian land driller that has been rising along with the surge in drilling in new oil and gas plays. The company is somewhat exposed to oil and gas prices, since when they rise, more firms want to drill. However, even though natural gas prices are low, Precision Drilling has been benefitting from the use-it-or-lose-it nature of leases prevalent in shale plays. This policy keeps rigs operating, even when it may be unprofitable for the owner. At nearly 70 times trailing earnings, shareholders may want to consider taking some profits. The Fool's investor community still likes Precision Drilling , and I'm going to continue watching this one.

Foolish bottom line
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