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 RealD (NYSE: RLD) plunged for real today, down by 17% at the low, after the company announced disappointing box office sales for June.

So what: The company said that box office sales in June for RealD-enabled screens was approximately $291 million, of which $158 million was domestic and $133 million was international. Revenue for the fiscal quarter should be around $838 million, of which $431 million was domestic and $407 million was international.

Now what: The June sales were down sequentially from $345 million in May, which bodes poorly considering how important the summer is for Hollywood. Consumer interest in 3-D movies may be waning, as consumers may be becoming pickier about what they watch in the format since the prices are higher. RealD received a handful of analyst downgrades today following the figures.

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