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: Want an up-close look at how crazy Mr. Market can be? Fool, I give you VirnetX (AMEX: VHC), which rose 15%, then gave it all back and then some. Shares of the communications security specialist were down slightly just before the closing bell.

So what: I can’t find a report that explains why VirnetX soared, but it may not matter. This is the eighth-most watched stock in our Motley Fool CAPS database, ranking ahead of such names as Electronic Arts (Nasdaq: ERTS) and Qlik Technologies (Nasdaq: QLIK). Anything can move a stock when it's watched this closely.

Now what: Whatever caused the pop, the euphoria had already come and gone as of this writing. The lesson? As sexy as VirnetX’s stock story is -- what could be better than cashing in on a trove of LTE patent treasures? -- investors are better served sticking to the fundamentals. VirnetX doesn’t have much to work with in that department. Do you agree? Disagree? Weigh in using the comments box below.

Interested in more info on VirnetX? Add it to your watchlist .

The Motley Fool owns shares of Qlik Technologies.Motley Fool newsletter services have recommended buying shares of Qlik Technologies. Try any of our Foolish newsletter servicesfree for 30 days.

Fool contributorTim Beyers is a member of theMotley Fool Rule Breakers stock-picking team. He owned shares of Qlik Technologies at the time of publication. Check out Tim'sportfolio holdings andFoolish writings, or connect with him on Google+ or Twitter, where he goes by @milehighfool. You can also get his insightsdelivered directly to your RSS reader. We Fools may not all hold the same opinions, but we all believe thatconsidering a diverse range of insights makes us better investors. The Motley Fool has adisclosure policy.