Individual stocks can rise 10%, 25%, or even higher in a short period of time. And they can fall just as far, just as quickly. For example, shares of storage products maker STEC tumbled nearly 39% Wednesday after the company warned that key customer EMC (NYSE: EMC) would carry over inventory into next year, potentially affectingfirst-quarter sales and earnings.

Big drops in share price can sometimes signal material defects or new risks. But at other times, they're simply pullbacks along with the larger pessimism facing the market today. Fortunately, we have Motley Fool CAPS, a great resource to help us understand the larger picture behind big price drops.

Is the sky falling?
CAPS contains more than just the crowd's opinions. Its best-performing members' votes count more in shaping each company's ratingthan do the picks of their poorer-performing peers. That way, investors can intelligently use the collective wisdom of more than 140,000 CAPS members to make better decisions.

We'll use CAPS' handy stock screening toolto quickly zero in on companies whose share prices have fallen at least 20% in the past four weeks and that have a market cap greater than $100 million and a betaof less than 3. If you want to run this screen for yourself, please do-- just keep in mind that the results will update with the market.

Company

CAPS Rating
(out of 5)

4-Week
Price Change

Boyd Gaming (NYSE: BYD)

**

(30%)

Alcatel-Lucent (NYSE: ALU)

**

(21.5%)

Advanced Micro Devices (NYSE: AMD)

** Continued...