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: Barnes & Noble (NYSE: BKS) popped 14% in intraday trading today on news that it plans to announce a new e-reader later this month.

So what: A Barnes & Noble SEC filing says the company "expects to make an announcement on May 24, 2011, regarding the launch of a new eReader device." The news comes on the heels of last week's upgrade of the company's Nook Color e-reader to an Android tablet -- a huge positive, in my opinion.   

Now what: The May 24 announcement could be an upgrade of the new Nook Color from the Froyo to the Honeycomb version of Android. Or it could be much ado about something as unexciting as a normal product refresh of B&N's basic e-reader. Today, investors seem to be operating on the old stock market adage "buy on the rumor, sell on the news."

Interested in more info on Barnes & Noble? Add it to My Watchlist.

Fool contributor Cindy Johnson owns no shares of any company named above. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.