Even on the market's worst days, buyout news and other short-term forces can send individual stocks up by 10%, 25%, even 50%.        

For example, shares of Facet Biotech jumped nearly 75% one day in early September, when Biogen Idec made its first unsolicited offer to buy the company -- an offer that has since been increased and hasn't been accepted.  

But beyond less-predictable events like that one are stocks with fundamentally compelling reasons for recent momentum. The trick is to find those stocks. That's where Motley Fool CAPS comes in.

The story behind the story
CAPS is no crowd of lemmings. Its best-performing members' opinions do more to shape each company's rating than the picks of their poorer-performing peers. Let's use the collective wisdom of more than 145,000 CAPS members to filter out the noise and find companies offering strong momentum.

We'll use CAPS' handy stock-screening tool to quickly zero in on companies with a price increase of at least 20% in the past four weeks, a market cap of greater than $100 million, and a beta of less than 3. Below is a sample of stocks that our screen returned. If you'd like, run this screen yourself -- just keep in mind that results may change as the market does.

Company

CAPS Rating
(Out of 5)

4-Week
Price Change

Huntsman

*****

27.7 %

General Steel (NYSE:GSI)

*****

20.1 %

Solarfun Power (NASDAQ:SOLF)

***

22.4 %

First Bancorp

**

29.2 %

American Superconductor (NASDAQ:AMSC)

**

24.8 %

Source: Motley Fool CAPS. Price return from Nov. 13 through Dec. 11.

Solarfun Power
It has been a volatile year for investors in Solarfun, and the company's recent earnings report, including record shipments and a profit to boot, contributed to the latest increase in the price. Like Canadian Solar (NASDAQ:CSIQ) and other peers, the company has been experiencing an increase in demand, and its increased shipments have offset falling selling prices.

Fourth-quarter shipments are expected to rise with a strengthening German market, and the company is joining a list of others such as LDK Solar (NYSE:LDK) and Suntech Power to benefit from China's solar subsidies. Solarfun Power announced that it signed a deal with a Chinese city government to build a 100-megawatt plant, and many investors like the potential in that country. Today, 92.3% of the 1,183 CAPS members rating Solarfun Power expect it to outperform the market.  

American Superconductor
After posting strong sales and earnings increases in each of its first two quarters, American Superconductor expects the momentum to continue for this year and forecasts an even bigger fiscal 2010, thanks to a growing backlog and lower costs. While General Electric (NYSE:GE) and China-based A-Power Energy Generation Systems (NASDAQ:APWR) recently won significant contracts to supply wind turbines in the U.S., American Superconductor has also thrived in China recently with sales of its wind energy systems and components, particularly to Sinovel Wind, its main customer there.

Despite American Superconductor's improved financials, Sinovel Wind accounts for a large portion of its revenue, which has some investors concerned. And even though the company is benefiting from the global push for alternative energy, CAPS members have kept its rating at no better than two stars since last year. Looking at the scorecard, only 80% of the 625 members rating American Superconductor are bullish on the stock today.

And you?
What's your story? Whether you buy the tale of a stock that's soaring or souring, your own research is more important than collective opinions. But these collective opinions can make your due diligence a whole lot easier.

Add your take on these or any of the 5,300 stocks that our 145,000-plus members have covered in Motley Fool CAPS. It's totally free to be a part of the community, and the payback is more than worth it.

The Motley Fool Stock Advisor service looks for companies with strong management poised to beat the market over the long haul. To see all the stocks that have helped Tom and David Gardner beat the market by 51 points on average, take a free 30-day trial.

Fool contributor Dave Mock has his own story, but there's no "happily ever after" at the end of it. He doesn't own shares of companies mentioned here. General Steel Holdings is a Motley Fool Global Gains recommendation. Suntech Power is a choice of Rule Breakers. The Fool's disclosure policy has the momentum of a freight train, but can stop on a dime.