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 GoPro Inc (GPRO -1.82%) were fading Wednesday, falling as much as 15% as the camera-maker's post-IPO rally finally fizzled.

So what: Shares of the high-tech camera-maker had more than doubled from its $24 IPO price after it kicked off trading last Wednesday, but the stock fell today on reports that short sellers were moving in. Stocks tend to be volatile in their initial trading days, but GoPro's fluctuations are even wilder than normal as Astec Analytics said that nearly 100% of the shares available for borrowing, and therefore shorting, have been borrowed, indicating many investors are betting on the stock to fall. 

Now what: Long-term investors in GoPro can probably ignore today's drop. While it's important to be aware of the short interest in the stocks you hold, heavily shorted stocks can also quickly spike on good news due to short squeezes from short sellers attempting to cover their bets. Even after the pop, shares still seem reasonably priced at a P/S of 6, and the company, which is only 10 years old, is already profitable. GoPro dominates the niche market of stunt and extreme sports-based video, and is set to begin collecting money from advertisers, which should give the company another valuable revenue stream. As video usage and wearable technology continues to grow in the Facebook/YouTube generation, I'd expect GoPro to thrive.