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 3-D movie technology specialist RealD (NYSE: RLD) sank 16% in intraday trading Friday, after its margin outlook for next year disappointed investors.

So what: While the company's first-quarter results managed to blow out Wall Street estimates, management's forecast of declining license gross margins for fiscal 2012 has Mr. Market concerned about RealD's future profitability. And with recent releases Kung Fu Panda 2 and Pirates of the Caribbean generating lackluster 3-D numbers, analysts are generally questioning the format's long-term appeal.

Now what: I'd continue to be cautious about buying into RealD. IMAX (NYSE: IMAX) -- which has also sold off recently -- remains the more established and fundamentally sound way to play all the concerns over a weak 3-D box office. RealD shares might be tempting, given their 40% price decline over the past few weeks, but when it comes to Rule Breaker investing, owning the top dog is almost always your best bet. 

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

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Motley Fool newsletter services have recommended buying shares of IMAX. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy always gets a perfect score.