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.

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

USEC (NYSE:USU)

(30.9%)

(33.9%)

*****

Infinera (NASDAQ:INFN)

(20.9%)

(38%)

*****

Dynamic Materials (NASDAQ:BOOM)

(16.8%)

(48.8%)

*****

Metalico (AMEX:MEA)

(15.1%)

(73.3%)

*****

China Natural Gas

(13.3%)

(6.2%)

*****

Pharmaceutical Product Development (NASDAQ:PPDI)

(10.9%)

(42.4%)

*****

China Medical Technologies (NASDAQ:CMED)

(8.6%)

(59.4%)

*****

Data from Motley Fool CAPS as of July 29.

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 Motley Fool Rule Breakers pick Infinera.

Why so blue?
Though Infinera did recently report earnings, we can't blame that announcement for the big drop in the stock. In fact, the company actually beat analysts' estimates.

A day before earnings were released though, an analyst at Jeffries & Co. issued a research report that claimed he was "95 percent sure" that Infinera competitor Huawei Technologies had lured away Level 3 Communications (NASDAQ:LVLT), which accounted for 25% of Infinera's 2008 revenue. So is this fellow a savvy researcher or a stock assassin? Only time will tell since we can't expect Infinera to cough up that information.

On the bright side, the importance of Level 3's business has come down significantly since accounting for 75% of Infinera's business in 2006. As management noted in the earnings release, the company has been continuing to add to its customer roster, including recently bringing on Japanese giant NTT.

Of course, if it's true, the loss of Level 3 would still be quite a blow.

What the bulls say
CAPS members may change their tune to some extent if it's revealed that Level 3 jumped ship on Infinera, but for now, the community is overwhelmingly bullish on the company's prospects. In all, more than 1,000 CAPS members have given Infinera's stock a thumbs up compared to just 22 who think the stock will underperform the S&P 500 index.

So what's all the hubbub about? All the way back in 2007, CAPS All-Star TMFBreakerJava put an enthusiastic thumb up on Infinera and pitched:

Optical switching on a chip is the breakthrough technology driving this company's explosive growth. Optimizing optical networks can greatly increase their throughput and Infinera's technology allows providers to do this in a cost-effective way. With the explosion in Internet traffic showing no signs of slowing down, the growth in demand for bandwidth should continue its rapid increase. When network owners can provide this bandwidth through inexpensive optimization rather than the laying of new fiber, the cost advantages are enormous. This is the proposition behind Infinera's explosive growth. Time to jump on board the rocket.

But here's the important question: Do you think the recent drop has created a good buying opportunity? Or will competitive pressures continue to weigh on the stock? 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 Infinera, 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:

Infinera is a Motley Fool Rule Breakers pick. Pharmaceutical Product Development is a Motley Fool Stock Advisor recommendation. Dynamic Materials is a Motley Fool Hidden Gems selection. The Fool owns shares of Dynamic Materials and Infinera. 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.