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, stock in Electronic Data Systems (NYSE: EDS) surged more than 29% only a few days after Hewlett-Packard (NYSE: HPQ) confirmed its interest in the business process services company with a $13.9 billion offer.

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 investors' opinions do more to shape each company's rating than the picks of their poorer-performing peers do. Let's use the collective wisdom of more than 100,000 CAPS investors to filter out the noise and find companies offering strong momentum.

We'll screen for companies with a stock price increase of at least 25% in the past month, a market cap of greater than $100 million, and a beta of less than 3. That'll keep us clear of the wild, pump-and-dump land of penny stocks.

Here's a sample of stocks our screen returned:

Company

CAPS Rating
(Out of 5)

1-Month
Price Change

Diana Shipping (NYSE: DSX)

*****

31.7%

Marvell Technology (Nasdaq: MRVL)

*****

34.4%

Google (Nasdaq: GOOG)

***

27.4%

Broadcom (Nasdaq: BRCM)

***

30.8%

Sprint Nextel (NYSE: S)

**

40%

Return data is calculated as the difference between the closing price on April 11 and the closing price on May 13, as per MSN Money's screen. Star rankings from CAPS.

Let's burrow through this list of stocks that have thumped the market in the past month and find the story behind the numbers.

Leaner and lighter
I've already put plenty of thought into multiple reasons why shares of struggling telecom services provider and Motley Fool Inside Value selection Sprint Nextel shouldn't see any positive momentum, but that was back when shares were trading at around the $13 level. Since then the business has been devalued dramatically, and shares bottomed below $6 apiece in March. It's been nothing but up since then, though.

While CEO Dan Hesse noted that the turnaround will take a long time, other events have investors singing a more bullish tune for Sprint Nextel lately. The main draw is the new WiMax partnership that has Sprint Nextel offloading its next-generation network initiatives into the new Clearwire. Shareholders have been badgering Sprint Nextel for months to do something to get the significant investments in WiMax off its books. If the deal goes through, Sprint Nextel's Xohm division and spectrum assets will be transferred into the new Clearwire in exchange for 51% ownership.

Some investors may think Sprint Nextel's time has come to revive and thrive, but others disagree. In CAPS, a solid contingent of pessimists still holds Sprint Nextel to a sub-par two-star rating, with nearly 36% of All-Star investors weighing in with bearish votes.

I'm on the side of the bulls at this point, though -- I think the worst is priced into Sprint Nextel and, even though the future still looks ugly, there's value in shares today.

Broad momentum
Another tech sector darling surging in the past month is broadband communications chip maker Broadcom. While the softening economy has affected spending across many industries and shares have drifted lower across the board, Broadcom has managed to show strength when others are at their weakest. In its most recent earnings report last month, Broadcom squeezed increased revenue from a diverse base of products to perform better than even management expected.

Some investors hedge on Broadcom's future -- not because of its solid product base and leadership in certain segments -- but because of its valuation. Broadcom holds a forward earnings multiple of just over 19 today, a hair ahead of its 18% expected growth rate. This may be behind the 56 bearish votes out of 613 registered in CAPS for Broadcom. I agree that shares aren't a bargain by any measure, but investors shouldn't expect stock in an aggressive innovator like Broadcom to ever come cheap.

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 5,600 stocks that our 100,000-plus investors 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 service looks for value in beaten down shares of companies like Sprint Nextel, which is a recommendation. To see other companies the analyst team believes are priced below intrinsic value, take a free, 30-day trial.

Fool contributor Dave Mock has his own story, but there's no "happily ever after" at the end. He owns no shares of companies mentioned here and is the author of The Qualcomm Equation. The Fool's disclosure policy has the momentum of a freight train but can stop on a dime.