I am always looking for a good deal, whether that means buying an extra box of Cocoa Puffs when they're on sale or pouncing on undervalued stocks. The idea that anybody would sell a stock for less than its worth may seem silly, but legendary value investor Ben Graham tells us, by way of allegory, how we can look out for these situations.

In The Intelligent Investor, Graham introduces readers to a crazy guy named Mr. Market. Mr. Market's game is to pay you house calls on a daily basis to offer to sell you interests in businesses he owns or to buy from you interests in businesses you own. Sometimes Mr. Market will show up at your door very excited and offer you premium prices for your holdings, while at other times he'll be totally depressed about the future and will offer to sell you what he has for as low as pennies on the dollar.

So to find some of the stocks that Mr. Market is depressed about, I've turned once again to The Motley Fool's CAPS investor community. Each of the companies below had been given a five-star rating (the highest) by our community of investors just 30 days ago:

Stock

30-Day Return

One-Year Return

Current CAPS Rating

Arch Coal (NYSE:ACI)

(18.2%)

(14.3%)

****

Peabody Energy (NYSE:BTU)

(15.3%)

(10.1%)

*****

Universal Stainless & Alloy Products (NASDAQ:USAP)

(15.3%)

32.3%

*****

Immucor (NASDAQ:BLUD)

(13.3%)

52.2%

****

Trinity Industries (NYSE:TRN)

(10.9%)

12.7%

*****

Steel Dynamics (NASDAQ:STLD)

(14.2%)

38.8%

****

Sonic (NASDAQ:SONC)

(12.1%)

2.0%

****

Data from Motley Fool CAPS as of June 26.

As the table shows, these stocks are all still very well-regarded by the CAPS community despite their underperformance over the past month. While these are not formal recommendations, they could be a great place to kick off some further research. I'll even get you started with some thoughts on a couple of these stocks.

Not the "Time of My Life"
While pretty much anybody even tangentially involved in the oil and gas business has been belting out a mean rendition of the classic song from Dirty Dancing lately, coal-producing stocks have found themselves clutching their knees in the corner and softly weeping.

Coal, according to the World Coal Institute, accounts for roughly 25% of the world's total energy consumption and 40% of electricity generation. After China, the U.S. is the world's largest coal producer, coughing up around 19% of the total global production.

Right now, the coal industry is having almost the exact opposite problem as the oil industry -- namely, many say there may be too much production. As coal producers continue to churn out new coal, inventories are starting to build, and there are some concerns over pricing pressure going into next year. It was this overproduction that spurred a recent downgrade of the sector by a Goldman Sachs analyst.

Not everyone agrees with this assessment, though. Everyone's favorite TV madman, Jim Cramer (who we track on CAPS), was quick to counter his alma mater, citing Democrats' recent support of an energy plan that includes coal-to-liquids technology. And Cramer is not the only one who thinks Goldman may be wrong, particularly from the political angle. One CAPS All-Star, northmichigan, has rated Peabody an outperform, saying that he "[believes] that coal will perform very well as our power needs increase, and the newly elected Democrats push for a fuel that is here in the U.S."

So do you think politics will power coal producers forward? Or will oversupply make their stocks sag? Let the community know what you think -- head over to CAPS and share your thoughts with the other 30,000 players currently part of the community. You can also check out the other stocks listed above, or any of the 4,700 stocks currently rated on CAPS.

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Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out Matt's CAPS portfolio here, or tune into his CAPS blog here. The Fool's disclosure policy imagined all the people living life in peace, even though it doesn't consider itself a dreamer.