I am always looking for a good deal, whether that means buying an extra box of Golden Grahams 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 (no relation to the cereal) tells us, by way of allegory, how we can look out for these situations.

In The Intelligent Investor, Graham introduces readers to a wacky chap 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 inconsolably depressed about the future and will offer to sell you what he has for as low as pennies on the dollar.

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
(out of 5)

VimpelCom (NYSE:VIP)

(17.6%)

(67.4%)

*****

Canadian Natural Resources (NYSE:CNQ)

(12.0%)

(52.3%)

*****

Mechel (NYSE:MTL)

(11.5%)

(84.9%)

*****

Cameco (NYSE:CCJ)

(10.6%)

(36.8%)

*****

Vale (NYSE:VALE)

(9.3%)

(49.4%)

*****

ConocoPhillips (NYSE:COP)

(8.9%)

(54.8%)

*****

Petrobras (NYSE:PBR)

(8.0%)

(42.3%)

*****

Data from Motley Fool CAPS as of June 22.

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 further research. I'll even get you started with some thoughts on Petrobras.

Why so blue?
As one of the largest oil companies in the world, it shouldn't be too surprising that the fortunes of Petrobras are tethered to the price of oil. As a result, not unlike Conoco and any of the other oil majors, Petrobras' stock took a nasty dip as prices plummeted late last year, and has been bouncing back alongside oil prices through much of this year.

But after more than doubling from their bottom, oil prices now look like they may be stalling just a bit. While geopolitical concerns -- particularly in major oil producer Iran -- have heated up lately, cooling comments about the global economy have had energy traders getting cautious on oil.

What the bulls say
Economic concerns may continue to be in the forefront for the next couple of years, but it seems likely that the fate of the world's energy supply will be a hot topic for many years to come. This has led many CAPS community members to heap outperform ratings on oil companies like Petrobras. Currently, Petrobras is a five-star stock, with more than 3,600 outperform ratings, versus just 65 underperforms.

CAPS member billddrummer gave Petrobras' stock a thumbs-up earlier this month and shared his thoughts:

The new oil field discovered off the coast looks to be a massive find--5 to 8 billion barrels of provable reserves. Not only that, the Brazilian government isn't afraid to exploit its natural resources, unlike the US. As the fields come on line later in 2009 and into 2010, the impact on the global oil supply will be material, helping to temper increases in gasoline next year. This find is primarily natural gas and light, sweet crude, optimum for making gasoline and diesel.

So here's the question: Do you think the recent drop has created a good buying opportunity? Or will the stock need to cool off further? Let the community know what you think -- head over to CAPS and share your thoughts with the other 135,000 members. Even if you'd prefer to pass on Petrobras, you can check out a couple of the other stocks listed above or any of the 5,300 stocks that are rated on CAPS.

More CAPS Foolishness:

Petroleo Brasileiro is a Motley Fool Income Investor selection. The Fool owns shares and has written covered calls on Cameco. Try any of our Foolish newsletters today, free for 30 days.

Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt likes in CAPS by visiting his CAPS portfolio, or you can connect with Matt on Twitter @KoppTheFool. The Fool's disclosure policy offers you one Schrute buck for reading this far.