Some stocks are one-hit wonders, making a big splash when they first appear, then quickly fizzling into obscurity or oblivion. But for other stocks, that initial big move is only a preview for even bigger and better gains to come.

Today we've listed three stocks that made some of the biggest upward moves over the past month and paired them with the ratings issued by our Motley Fool CAPS community. The higher each stock's rating, the greater CAPS members' faith in that company's ability to keep on beating the market.

Stock

1-Month Change^

CAPS Rating
(out of 5)

Aeterna Zentaris (Nasdaq: AEZS)

119.3%

****

Javelin Pharmaceuticals (NYSE: JAV)

63.4%

****

Neuralstem (NYSE: CUR)

60.7%

**

^ From April 9 to May 10.

As the markets whipsaw to changes in consumer sentiment, there will be weeks like this one, where we see gains that are exceptionally ahead of the pace of the movers and shakers of prior weeks. So before we get shaken out again, let's see why the CAPS community thinks some of these companies might continue to outperform the market.

A mighty temblor
Last week, Keryx Biopharmaceuticals (Nasdaq: KERX) caused a sensation when its colorectal cancer therapy, perifosine, received fast-track status from the FDA. However, the market's euphoria seems premature at best since drugs getting the fast-track designation often come up empty as they wind their way through phase 3 trials.

Yet AEterna Zentaris, which licenses perifosine to Keryx, is enjoying a coattails effect. CAPS member crj24 suggests AEterna is better-positioned than its licensee, as it has an exciting pipeline:

They have three drugs in phase 3, 3 in phase 2 and 3 in phase 1. Persifone will be FDA approved within a year. This stock will follow in Keryx footsteps untill after Persifone is approved. [Aeterna Zentaris] is better long term unless Keryx buys them out.

A buyout could indeed come, as Keryx might want to ensure sole access to the drug. A similar situation occurred this week and it's why Javelin Pharmaceuticals made the shakers cut. Hospira (NYSE: HSP) agreed to purchase the pharmaceutical company to ensure it wouldn't miss out on Javelin's nonopioid analgesic, Dyloject, which is used in pain management.

Last December, Myriad Pharmaceuticals (Nasdaq: MYRX) sought to acquire Javelin in a $90 million stock swap, but Hospira came in with a much higher $141 million all-cash bid. When Myriad refused to raise its offer, Javelin officially terminated the merger agreement, and Hospira agreed to pay a $4.4 million breakup fee to Myriad.

More than 93% of the CAPS members rating Javelin believe it will outperform the markets. That's more than the 87% giving the thumbs-up to Hospira, but less than the 97% voting bullishly on Myriad.

Head over to the Hospira CAPS page and let us know whether its winning Javelin will inoculate it against any market pain.

Still feeling the aftershocks
Another stock caught up in the excitement of FDA clinical trials is stem-cell researcher Neuralstem, which got the go-ahead last September to begin phase I trials of its spinal cord stem cells to treat ALS (aka Lou Gehrig's disease). The stock has been on a fairly continuous rise since then and got another boost when a patient undergoing its treatment was recently featured on CNN.

Highly rated CAPS All-Star geneticbiscuit talks about the difficulties of proving a treatment's effectiveness:

Probably a bit early on this underperform call, but this recent run on news of entering Phase I trials for their stem cell treatments for ALS is a bit ridiculous.
With less than 5 million in the bank and a burn rate of about that per quarter, they'll have to come up with cash soon...and with all of the recent press I smell a secondary offering...
Also, while demonstrating safety is a good first step (Phase I), getting therapeutic significance in later trials is a completely different beast, a beast that has eaten many a biotech over the years.

While Neuralstem was the first stem-cell company to apply its research to the treatment of ALS in clinical trials, the industry is rife with potential. Cytori Therapeutics (Nasdaq: CYTX) is perhaps one of the better-known research outfits in the field, and others are looking forward to research dollars flowing their way, too.

Shake, rattle, and roll
With these stocks shaking the market this past month it pays to start your own research on them at Motley Fool CAPS. Read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from a stock's CAPS page.

Try any of our Foolish newsletter services today, free for 30 days.

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. You can shake, rattle, and roll The Motley Fool's disclosure policy, but it still won't break.