Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Computer Sciences (NYSE: CSC) plunged as far as 15.1% overnight on very heavy trading.

So what: Second-quarter earnings were strong but sales looked weak, and management slashed full-year earnings and sales guidance based on this quarter's business trends. Blame Uncle Sam: "The Public Sector business continues to be affected by the Federal budget uncertainty."

Now what: The company competes with the likes of IBM (NYSE: IBM) Global Services, Hewlett-Packard (NYSE: HPQ) Enterprise Services, and Accenture (NYSE: ACN) in the hotly contested IT services sector. I suppose it would be unfair to expect great shakes from Computer Sciences at a time when even Big Blue isn't firing on all cylinders. That being said, Computer Sciences has earned the trust of your fellow Foolish investors and scored a perfect 5-out-of-5 CAPS stars. To learn more or even weigh in with your own views, just click here to swing over to Computer Sciences' CAPS page.

Interested in more info about Computer Sciences? Click here to add it to My Watchlist.

Fool contributor Anders Bylund holds no position in any of the companies mentioned. The Motley Fool owns shares of International Business Machines. Motley Fool newsletter services have recommended buying shares of Accenture. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinion, but we all believe that considering a diverse range of insights makes us better investors. Check out Anders' holdings and bio, or follow him on Twitter and Google+. We have a disclosure policy.