"We simply attempt to be fearful when others are greedy and to be greedy only when others are fearful." -- Warren Buffett

Of all the Oracle of Omaha's orations, this one holds a special place in Foolish investors' hearts. When looking to bag a bargain, a panicked sell-off by jittery investors offers you a great chance to snap up stocks on the cheap.

In the short term, professional traders' pessimism can become a self-fulfilling prophecy. Desperate institutions lower their asking prices to get rid of a stock, prompting buyers' bid prices to fall in tandem, creating the very price decline that both sides feared in the first place -- until the selling stops.

Until it does, savvy investors can "get greedy," snapping up bargains from these fearful sellers. (Assuming they really are bargains.) In today's column, we'll see which stocks Wall Street's motivated sellers are most frantic to unload. Once we've compiled this shopping list of potential picks, we'll check them against the collective intelligence of Motley Fool CAPS.

Today's contenders include:

Companies

Recent Price

CAPS Rating
(out of 5)

ImmunoGen  (NASDAQ:IMGN)

$7.82

****

LDK Solar  (NYSE:LDK)

$8.21

***

Tessera Technologies 

$20.26

***

Career Education 

$24.26

**

AnnTaylor 

$13.16

*

Companies are selected from the "Institutional Ownership Down Last Month" list published on MSN Money after close of trading on Friday. Recent price provided by Yahoo! Finance. CAPS ratings from Motley Fool CAPS.

Time to panic?
Wall Street traders are selling these stocks in droves, and if you ask the 145,000 odds-makers on Motley Fool CAPS, they'll tell you that's probably the right call. Career Education and AnnTaylor in partiuclar score low marks within the CAPS community, while LDK and Tessera merit just a shrug and a three-star rating.

One place where many investors differ with the "professional" assessment, however, is on cancer researcher ImmunoGen. A lot of folks believe that ImmunoGen will win the race for the cure -- and that buyers today can run away with the profits. Let's find out why.

The bull case for ImmunoGen
CAPS member NetscribeHealthC introduced us to ImmunoGen way back in 2007 as a developer of "antibodies to deliver a potent cytotoxic agent specifically to treat cancer cells. Its collaborative partners include [Amgen (NASDAQ:AMGN), Biogen Idec (NASDAQ:BIIB) ... sanofi-aventis (NYSE:SNY)]. It owns 46 patents issued in the US and over 46 pending US patent applications covering the company's proprietary design, synthesis, development and manufacturing of monoclonal antibody (Mab) drug conjugate therapeutics."

One of these partners, Roche, struck gold last month when a drug it's been working on in conjunction with ImmunoGen showed "positive results" in treating advanced cases of breast cancer. This news inspired CAPS All-Star zzlangerhans to argue that: "T-DM1 has to be taken seriously as an anti-cancer agent. ... [Even so, a] long road lies ahead, as ... Partner Roche won't initiate a phase III trial for T-DM1 until May 2010."

Other Fools, including ALangadakis, believe we won't have to wait that long, though, suggesting that ImmunoGen has proven its value, and will soon be: "bought out" by either a partner or rival.

Ignorance is bliss
And me? What do I think about ImmunoGen? Well, I think it's burning cash at the fastest pace it ever has -- more than $24 million up in smoke over just the last 12 months. On the other hand, I think it's got a strong financial partner in Roche, and a good $60 million of its own cash on hand, with which to finance ongoing research.

But the honest truth, Fools, is that I just don't know what to think about ImmunoGen. Ask me about Pfizer (NYSE:PFE) or Merck (NYSE:MRK) -- a drugmaker with real products on the market, profits pouring in, and a steady stream of dividend payments going out, and I'll give you an informed opinion. But I have the devil's own time trying to wrap my head around cash-burning R&D shops like ImmunoGen. I simply have no idea whether the products will find a market, and if they do, whether the profits that'll result tomorrow justify the share price on offer today.

Time to chime in
Fortunately, I don't have to know what to think about ImmunoGen. Here on CAPS, I've got 145,000 (and growing) fellow investors -- many of whom know a whole heckuvalot more about biotech than I do -- to rely on. If you're one of those clever Fools, then here's your chance to educate the rest of us. Click through now, and tell us what you think about ImmunoGen.

Motley Fool CAPS: It's fun, it's free, and it just might make you famous.

Fool contributor Rich Smith does not own shares of, nor is he short, any company named above. You can find him on CAPS, publicly pontificating under the handle TMFDitty, where he's currently ranked No. 1,535 out of more than 145,000 members. The Fool has a disclosure policy.

Pfizer is a Motley Fool Inside Value recommendation.