Some stocks are one-hit wonders, making a big splash when they first appear, only to quickly fizzle 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 compiled 10 stocks that made some of the biggest upward moves over the past month. We'll then pair that list 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.


4-Week % Change

CAPS Rating (Out of 5)

Air Transport Services Group



US Geothermal



ReneSola (NYSE:SOL)



Allied Irish Banks (NYSE:AIB)



AgFeed Industries (NASDAQ:FEED)



Satyam Computer Services (NYSE:SAY)



Yingli Green Energy (NYSE:YGE)






Antigenics (NASDAQ:AGEN)






Data from Motley Fool CAPS as of June 10.

More than half of these stocks carry four-star or better ratings, so let's investigate why the CAPS community thinks they might outperform the market.

A mighty temblor
When a stock suddenly roars to life -- as Antigenics did after it said patients lived markedly longer using its kidney cancer treatment -- it's not unusual that they become poised to plunge soon thereafter. Such givebacks are part of the normal course of things, as investors cash out some profit. The greater challenge lies in maintaining the justification for the surge in the first place.

If the results of its Oncophage drug bear out, Antigenics' stock might just continue its upward swing. According to the company, patients with an intermediate risk of disease recurrence showed about a 46% lower risk of death following use of Oncophage for their kidney cancer. That result should help push along the biotech's marketing application with the European Union. Right now, the drug is available only in Russia, and recently the company signed a three-year agreement for distribution there. But Antigenics is looking for a late-2009 go-ahead in the E.U.

However promising these therapies might be, there's still a long road ahead before the drug achieves commercialization in the E.U. or here in the States. In the interim, some investors, such as CAPS All-Star member Vavoom11, suggest that you "short the pop" in the stock price. All-Star member zzlangerhans, meanwhile, says investors should remain very skeptical:

Oncophage failed phase III trials years ago and the company has been stringing investors along with post hoc subset analyses and publicity stunts like getting approval in Russia, which has generated no meaningful revenue. God only knows how much truth … was in their recent survival advantage claims at [the American Society of Clinical Oncology]. They've long ago lost any credibility with anyone who has followed biotech for more than a couple of years.

The CAPS Biotechnology tag has certainly been buoyed by movement in the likes of Antigenics and Hemispherx BioPharma. The 239 companies making up the tag have risen by more than 15% over the past month, far outstripping the 3% gains in the S&P 500. The tag for Micro Cap stocks -- which also includes Antigenics -- has been on a roll, too, having climbed by more than 18% this month.

Shake, rattle, and roll
With these stocks shaking the market over the 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.

Allied Irish Banks is a Motley Fool Global Gains selection, and the Fool owns shares of it. Try any of our Foolish newsletter services free for 30 days.

Fool contributor Rich Duprey has no financial position in any of the stocks mentioned in this article. You can see his holdings. You can shake, rattle, and roll The Motley Fool's disclosure policy, but it still won't break.