You've seen it before -- the crazy moves, the big numbers, that look in their eyes. That's right, I'm talking about the market's big single-day movers. If it's not one stock making you fleetingly jealous with a 70% price jump in one day, it's another stock plunging 50% in a matter of hours and making you wonder whether there's not something vaguely criminal about it.

Now is your chance to play judge and jury for these stock market offenders. I will present the case of four rowdy stocks, and you'll have the chance to visit the Motley Fool CAPS investing service to make your own call.

Stock

Yesterday's Offense

CAPS Rating

La Jolla Pharmaceutical (NASDAQ:LJPC)

30.7%

Needs more votes!

OMNI Energy Services (NASDAQ:OMNI)

17.6%

*****

New Century Financial (NYSE:NEW)

(25.0%)

*

Bionovo

(19.1%)

*

Data from Motley Fool CAPS as of March 8.

So ladies and gents, I present you with the following cases and leave the judgment to you. When you have your verdict, head right on over to CAPS and share your thoughts with the rest of the community.

Case LJPC
La Jolla Pharmaceuticals is a biopharma company developing drugs for antibody-mediated diseases. Specifically, the company is in clinical trials with its drug Riquent, a treatment for lupus -- an autoimmune disease that causes the immune system to attack various tissues in the body.

Many of the currently approved treatments for lupus involve nasty side effects such as the suppression of the entire immune system, which can leave the patient susceptible to infections. Riquent has been designed to control the effects of lupus without having to shut down the entire immune system.

Yesterday, La Jolla announced some positive interim results from the phase 3 trial for Riquent, and shares shot up 31%. Data so far from the study has shown a statistically significant improvement in levels of antibodies to dsDNA (a typical measure of the presence of lupus in a patient) in patients on Riquent versus those on a placebo. The study has also shown higher reductions in antibodies to dsDNA for patients on higher doses of Riquent.

While this is certainly good news, with the drug development companies it's never over until -- well, you know. La Jolla has been through a phase 3 trial with Riquent before, and though it showed reductions in antibodies to dsDNA, it failed to meet primary and secondary endpoints. Enrollment for the current study, which is testing higher doses of the drug than the previous phase 3 trials, is expected to continue through the end of 2007.

Judge this case.

Case OMNI
Our next case brings us to OMNI Energy Services, an oilfield-services company. OMNI operates in two segments: one that provides onshore seismic drilling services, and a second that primarily offers hazardous- and nonhazardous-waste-management services for offshore drilling.

OMNI's pop came after the company released its 2007 outlook, where it said it expects revenue to be up 80% over 2006. The top end of the company's projected net income for '07 is $17 million, which would put valuation on a forward basis at just less than 9.5 times net income. The stock responded by jumping for joy to the tune of 18%.

CAPS players were hardly surprised -- the stock has a five-star rating, with 218 bulls to only four bears. Among the interesting chatter going on at the OMNI CAPS page, the top bull pitch has WCWlooky, a CAPS All-Star, sharing this from back in January:

"I am not sure on the timing or catalyst that will send oil and gas higher and higher. I do feel that it will happen because of limited supply, growing demand, and political turmoil in many regions of production."

Judge this case.

Case NEW
Oh, New Century, what are we going to do with you? The company is one of the subprime lenders starting to feel the effects of a little too much excitement during the U.S. housing boom over the past few years. Aggressive lending to borrowers who just aren't all that likely to make good on their loans is bruising the industry, and the hits just seem to keep on coming.

Yesterday, one of New Century's board members, David Einhorn, resigned. Einhorn is a principal at the hedge fund Greenlight Capital and had joined the New Century board to try to shake things up when he thought the stock was unduly depressed. Greenlight currently owns more than 6% of New Century -- that's gotta hurt.

Also yesterday, New Century announced that it is not accepting any new loan applications. With a dive-bombing share price and an almost complete lack of investor confidence (many believe New Century is well on the road to bankruptcy), the company said that it now has very limited capacity to fund new loans.

And this is all on top of the fact that the company is being investigated for some funny-smelling stock trades.

Judge this case.

Case BNVI.OB
And now we come all the way back around to Bionovo -- a stock that was on the other side of the table in the last episode of "You Be the Judge." Bionovo is a developer of drugs for women's health and cancer treatment. Its leading drug candidate, MF101, is a treatment for menopausal hot flashes and night sweats that is designed to have little or no dangerous side effects.

In yesterday's trading, Bionovo was demonstrating the stomach-wrenching roller coaster that can sometimes come when investing in smaller-cap stocks. With no news, Bionovo's stock slipped almost 20%. Of course, the last time we looked at this stock it was up 27% -- also on no news.

Oh, and just for the record, I always get a funny feeling from companies that put their stock quote on the front page of their website.

Judge this case.

Stay tuned for the next episode of "You Be the Judge," and until then, keep up your judgmental ways.

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When it comes to short-term trading, Fool contributor Matt Koppenheffer is less Jesse Livermore and more Uncle Jesse, though he doesn't mind a little volatility to spice up his life. He does not own shares of any of the companies mentioned. The Fool's disclosure policy is here for your own good and will never judge you -- no matter how bad a hair day you're having.