"Don't catch a falling knife," as the old saw commands. (Pardon my mixing a cutlery metaphor.) The idea of buying a former superstar stock at a discount price certainly has its attractions, but you've got to make sure you catch the haft -- not the blade. That's where Motley Fool CAPS comes in.

Today, we once again stand beneath Mr. Market's silverware drawer, measuring which knives have fallen the farthest. Then we'll call on CAPS to ask which of these stocks -- if any -- Foolish investors believe are ready for a rebound. Let's meet today's list of contenders, drawn from the latest "52-Week Lows" list at WSJ.com:

Company

52-Week High

Recent Price

CAPS Rating (out of 5)

Petrobras (NYSE: PBR)

$53.46

$34.30

*****

DryShips (Nasdaq: DRYS)

$8.64

$4.70

***

Bunge (NYSE: BG)

$74.04

$47.84

***

Companies are selected from the "New Highs & Lows" lists published on WSJ.com on Friday last week. 52-week high, recent price, and CAPS ratings from Motley Fool CAPS.

Down and out in Brazil
It's been an interesting few weeks for stock investors (and what is it the Chinese say about living in "interesting times?") Nearly three weeks ago, a sharp, midday sell-off drove the Dow down 1,000 points for no particular reason. Today, the whole dang stock market is down 10% and more from its high -- a bona fide "market correction." And yet, investors are not at all certain the market is correct to be selling all stocks equally.

Take Bunge for instance. Its recent weakness notwithstanding, CAPS All-Star udflyerz thinks this is a great stock to own "for the longterm. [Its] recent purchase of Brazilian sugar producer is helping as sugar prices are at or near all time highs." 

Or consider the case of DryShips. CAPS member SCCC2008 believes that: "the dry bulk shipping index is very undervalued," and predicts "a large upswing in the broad sector over the second half of 2010 and well into 2011/2012 as the Greek debt crisis calms down and shipping improves." (SCCC2008 believes we'll see similarly strong performance at shippers Eagle Bulk (Nasdaq: EGLE) and Excel Maritime (NYSE: EXM), in addition to DryShips.)

And yet, these two investors appear to be the outliers. With both Bunge and DryShips scoring only three out of five stars on the CAPS index, it appears most investors feel significantly less enthusiastic about the stocks' prospects. But not so with five-starred Petrobras ...

The bull case for Petroleo Brasileiro
Ever since the Deepwater Horizon drilling rig exploded a month ago, it's been rough sailing for deep-sea oil drillers. The company that leased the rig involved in that incident, BP (NYSE: BP), has lost well over a quarter of its market cap in the space of just one month. (And may now be a bargain in consequence.)

But it hasn't been the only victim. Petrobras has also taken some hits as sentiment turns negative across the oil industry, and according to CAPS member jimbendt, not just because of what happened to BP: 

Unfortunately, they paid dearly for drill rig contracts at market peak. New deep water rigs coming out of Korean shipyards won't help matters much. But oil is the chief commodity looking forward and he who puts his/her arms around large quantities of oil will be king.

WiseChoice4u2 adds that Petrobras' budget looks "stretched." But at the same time, the company boasts: "Proven reserves," is a "Good dollar play," and has a "China connetion."

Long story short, FromTheBottomsUp concludes, "this is a no brainer and everyone should own a piece" of this "Major player in an emerging market."

Great investors think alike
Just last week, my fellow Fool David Lee Smith made a similar argument in Petrobras' favor. In his review of the company's fiscal-first-quarter performance, Dave noted the company's 23% increase in profits on 18% revenue growth as two great reasons to own the stock. More important than what Petrobras has done, though, is what it may still do in the future.

Dave noted that Petrobras is promising to up its production by some 22% by volume this year. If oil prices rise from their present depressed levels, this promises even greater revenue growth, and still higher profits. And the story just gets better the further out you go. Last week, Brazil's national oil regulator confirmed that Petrobras has discovered two new major oilfields off the Brazilian coast. While details are sketchy, it sounds like Petrobras may have located upward of 10 billion new barrels of crude for the taking.

Foolish final thought
Now, Petrobras (and its 10.3 billion barrels of proven oil reserves) already compare pretty favorably to the valuation on fellow oil major ExxonMobil (NYSE: XOM). Given this, the addition of new reserves that could potentially double Petrobras' oil holdings has to be taken as a positive. And the fact that these new discoveries don't seem to be reflected in any uptick to the company's share price -- a double bargain.

To me, this sets up the possibility for a strong bounce-back in the stock, just as soon as the blowback from BP's disaster dissipates. But that's just my opinion.

What's yours?

Petroleo Brasileiro is a Motley Fool Income Investor selection, but Fool contributor Rich Smith does not own shares of any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 451 out of more than 160,000 members. The Fool has a disclosure policy.