You saw the headlines. You know your stock price made a big move. But what does that portend for your investment's future?

By pairing the latest news with the collective wisdom of our 170,000-strong Motley Fool CAPS investing community, we might be able to discover whether your stock's latest exploits are a short-term hiccup -- or the start of a much bigger trend.

The following stocks have all made big moves recently:

Stock

CAPS Rating
(out of 5)

Change Past Week

XenoPort (Nasdaq: XNPT) *** 35.0%
China Shen Zhou Mining (NYSE: SHZ) *** 31.9%
Star Scientific (Nasdaq: CIGX) ** (25.9%)

Source: finviz.com, Motley Fool CAPS. Change from April 6 to April 13.

It's estimated that as much as 10% of the U.S. population has restless leg syndrome, a neurological disorder characterized by a need to move your legs to relieve the discomfort that overwhelms them. It often occurs at night just as the person is drifting off to sleep.

Dopamine-based treatments for Parkinson's disease, such as Merck's Sinemet, GlaxoSmithKline's Requip, and Boehringer Ingelheim's Mirapex, have been found to be effective in reducing symptoms in 99% of restless leg syndrome sufferers. Pfizer's (NYSE: PFE) Neurontin, an anticonvulsant used to treat seizures, is another successful restless leg syndrome treatment. Trial lawyers, however, have attacked many of the dopamine-related drugs as causing other problems.

Although XenoPort navigated the minefield of FDA approval for a modified-release formulation of Neurontin called Horizant, because the field is so crowded there seem to be limits to the revenues it can realize. There's talk of broadening the indications for which Horizant can be used, such as for post-herpetic neuralgia (PHN), which Depomed (Nasdaq: DEPO) treats with another Neurontin offshoot, Gralise. Critics of the theory say XenoPort could only wrangle incremental growth out of it.

With the safety issues that originally prompted the FDA to issue a complete response letter to XenoPort for Horizant, CAPS member theslice says no doctor would prescribe it over Gralise:

Gralise label is 100 times better than Horizant, whose side effects are comparable to generic gabapentin. No doctor would prescribe Horizant over Gralise for something like PHN or pain(off-label). The very much reduced side effect profile of Gralise makes it much more attractive for older patients with PHN.

While XenoPort's stock initially jumped to over $11 a share, it has fallen 25% from those highs. Let us know on the XenoPort CAPS page whether investors will become restless looking for the next catalyst for growth.

A short course in poor PR
Sometimes the market is just nuts. Not manic, like Ben Graham said, but bat-guano crazy. Take, for example, the continued insistence by investors that China Shen Zhou Mining ought to benefit from the rare-earth element craze sweeping Molycorp, Rare Element Resources (NYSE: REE), and other supposed plays in the space. The company mines fluorite, which while relatively rare, is not a rare-earth element.

In fact, in response to one analyst's contention that China Shen Zhou was another dangerous small-cap Chinese stock like others we've seen out of China lately, the company issued a shareholders letter that specifically says it's not a rare-earth-element company and has never pretended to be one (read it for yourself here). That the market continues to accord it rare-earth status indicates why it needs to be locked in the attic with its crazy uncle.

Highly rated CAPS All-Star TSIF thinks investors need to be sent to a re-education camp to understand the difference between fluorite and rare-earth elements:

GeeSHZ.....NOT AGAIN! Repeat after me people. You brush your teeth and flourinate your water with China Shen Zhou Minings product which they can barely extract at break even prices. They have no rare earths! They get mentioned in rare earth articles when rare earths are doing one of their own insane dances and off they go again. New bagholders who can't be bothered to do some DD. Flourite may help protect against tooth decay but China Shen Mining will produce a DECAY in an investors portfolio.

Head over to the China Shen Zhou Mining CAPS page before the rush to downgrade the stock when the inevitable correction hits.

No assurance on veracity
While the FDA did say Star Scientific's new "healthy" cigarette technology will not fall under the same regulations that govern cigarettes, cigarette tobacco, and smokeless tobacco from Altria (NYSE: MO) and Reynolds American, as CAPS member expm1 noted, it's what it didn't say that may matter more:

The FDA has said that these products will not be regulated as tobacco. The FDA has not said what regulations the products will fall under. The possibility exists that the FDA will consider them un-registered drugs and stop Star from selling them.

With the markets selling down Star's stock since the approval was granted, it may be investors are taking that possibility into account. You can see if its hope goes up in smoke by adding Star to your watchlist.

Pfizer is a Motley Fool Inside Value recommendation. GlaxoSmithKline is a Motley Fool Global Gains selection. The Fool owns shares of Altria Group and GlaxoSmithKline. 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.