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

For example, shares in Sequenom (NASDAQ:SQNM) shot up 58% one day recently on no real concrete news.

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 135,000 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 stock price increase of at least 25% 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

ClickSoftware Technologies (NASDAQ:CKSW)

*****

29.4%

RF Micro Devices (NASDAQ:RFMD)

****

50.0%

Accuray

****

28.6%

Human Genome Sciences (NASDAQ:HGSI)

***

43.0%

Palm (NASDAQ:PALM)

*

29.1%

Source: Motley Fool CAPS. Price return from May 22 through June 18.

RF Micro Devices
Radio frequency component and semiconductor manufacturer RF Micro Devices supplies a diverse list of customers in the wireless industry, including Motorola (NYSE:MOT) and Samsung. But its top line is heavily driven by Nokia (NYSE:NOK), which represented about 52% of its revenue in fiscal 2009.

Even though it reported wider losses in its most recent earnings report, RF Micro's shares have made big gains over the past few months as it said demand for its products have been better than expected in the current quarter. Also, its latest, higher-margin products are accounting for an increasing percentage of total revenue

The company has worked to cut costs, and expects to generate free cash flow of $80 million to $120 million this fiscal year. Analyst sentiment has also increased, predicting profitability this year compared to a previous forecast of a $0.03-per-share loss.

While some CAPS members remain concerned about the company's financials, many are encouraged by the potential upside as demand picks up in the smartphone market. Indeed, according to the Semiconductor Industry Association, global semiconductor sales rose for the second consecutive month, increasing 6.4% in April.

Today, nearly 95% of the 499 CAPS members rating RF Micro Devices are expecting it to continue its market-beating ways and outperform the market.

Human Genome Sciences
Human Genome Sciences reported a huge boost in revenue in the first quarter, with its anthrax drug, ABthrax, and it recently released more good news about a continuation of the phase 2 trial of its systemic lupus erythematosus (SLE) drug, Benlysta, being developed with GlaxoSmithKline. But even though the tests have been progressing well, it's fighting tough odds, as there hasn't been a drug approved to treat lupus in several decades.

Top companies like Genentech and Biogen Idec took a shot against lupus nephritis and Teva Pharmaceutical failed against SLE, with many promising efforts showing good traction early but then faltering in later-stage trials. Two of Human Genome Sciences' phase 3 trials are expected to finish in July and November, and many investors have taken the long-shot bet that could pay off big if the later-stage tests are a success.

At this point, 90% of the 355 CAPS members rating Human Genome Sciences remain bullish on the stock.

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 135,000-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 Inside Value team looks for oversold stocks that are selling at bargain prices well below their intrinsic value. To see the full list of companies recommended today, 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 owns shares of Motorola. Nokia is an Inside Value recommendation.The Fool's disclosure policy has the momentum of a freight train, but can stop on a dime.