Resist the urge to high-five everyone in the cubicles next to you. Your stock may have just strapped on a rocket pack and taken off for the moon, but smart investors won't celebrate until they know that upward leap was justified. Without a fundamental basis for the bounce, these stocks can quickly make the return trip down.

Is now the time to lock in profits, or is this just the first step toward even higher valuations down the road? Let's examine several stocks that just hit the afterburners, and see whether they're truly headed into orbit:

Stock

CAPS Rating (out of 5)

Monday's Change

Clincal Data (Nasdaq: CLDA)

*

67.5%

Rexahn Pharmaceuticals (NYSE: RNN)

**

22.3%

China Biotics (Nasdaq: CHBT)

**

12.5%

The market jumped 108 points yesterday, or nearly 1%, as a buyback announcement by Intel (Nasdaq: INTC) helped fuel optimism that maybe the earnings season won't be so bad after all. Stocks that went up significantly more, however, are even bigger deals.

The devil's in the details
As mercurial as the FDA has been these days, getting your drug approved by the regulatory agency is always a big deal, whether you're a pharmaceutical giant like Pfizer (NYSE: PFE) or a small cap upstart like Clinical Data. Just ask MannKind (Nasdaq: MNKD), which thought it was moving toward approval for its inhaled insulin therapy Afrezza, only to have the FDA come back and say it wanted more trials done. Pfizer's known the feeling of rejection a time or two, also.

Clinical Data hit the lottery, though. The agency said its major depressive disorder treatment Viibryd was good to go. Clinical Data aims to have the drug in the hands of pharmacists by the second quarter. The U.S. market for antidepressants was approximately $12 billion in 2009, with more than 212 million prescriptions written.

While CAPS member EPS100Momentum likes the domestic revenue potential for Clinical Data, he's also looking at the big picture -- its worldwide opportunity:

According to articles I have been reading: Viibryd will have $1 Billion potential sales in USA alone. Once approved in other countries (other nations usually follow US FDA path) The potential sales will be in the multi billions per year worldwide. But for now the drug is entering a $12 billion market in the USA.

On the Clinical Data CAPS page, tell us why you're no longer depressed about its potential.

Making it to the big time
Rexahn Pharmaceuticals got a vote of confidence of another sort when Teva Pharmaceuticals (Nasdaq: TEVA) disclosed that it had taken a 6.3% position in the biotech, which is developing drugs for treating cancer and CNS disorders.

Rexahn will use the cash infusion to fund R&D for its pre-clinical-stage anticancer compound RX-3117. In June 2009, the biotech signed an agreement with Teva to purchase shares of its stock to fund the research, and it bought an initial tranche of 3.1 million shares that September. Its disclosure the other day that it bought an additional 2.3 million shares also allows Teva to purchase a third tranche, valued at $750,000, if Rexahn successfully completes an exploratory early-stage clinical study of the compound.

Although Rexahn met with disappointment last year with its experimental depression drug Serdaxin, CAPS member bonko1 still believes its pipeline of drugs will carry it forward.

You can watch Rexahn's progress by adding the stock to your watchlist. We'll gather all the Foolish news and analysis about it in one place, just for you.

Squeezed to death
A day after its stock fell 20%, China Biotics became a top gainer. The company reported preliminary third-quarter revenues of $32 million to $33 million, ahead of analyst estimates. At the high end, the probiotics distributor expects top-line growth north of 43% year over year, and 5% more than what Wall Street was anticipating.

Of course, there are still many questions hanging over the company's financials, after skeptics questioned the veracity of its customer list. The accusations took a toll on China Biotics' stock, but highly rated CAPS All-Star member throwerw has noted that management has retired a substantial amount of convertible debt, which could put the growing list of short sellers in an untenable position:

Management has been returning capital to shareholders by retiring $29 million worth of convertible debt back in December and buying back stock at a rate of $2 million per month. That means less shares in the float, less ammunition for the shorts. Volume is drying up, which is the last thing shorts want. Days to cover is now around 13, and any shorts initiated in the past 7 months are underwater.

Going into orbit
It pays to start your own research on these stocks on Motley Fool CAPS, where you can read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from the stock's CAPS page. Then you can decide for yourself whether your stock's headed for reentry, or off to infinity and beyond.

Intel and Pfizer are Motley Fool Inside Value recommendations. The Fool owns shares of and has bought calls on Intel. Motley Fool Options has recommended buying calls on Intel. The Fool owns shares of Teva Pharmaceutical Industries. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings here. The Motley Fool has a disclosure policy.