What's happening: Shares of Ambarella (NASDAQ:AMBA) were up 9.5% as of 11:00 a.m. Tuesday after an analyst at Canaccord Genuity defended the company following negative commentary from short-seller Citron Research, which caused the stock to fall yesterday.

Why it's happening: As I suggested yesterday, it didn't help Citron's case that the language in its negative report seemed overly sensationalized. But Canaccord Genuity's Matthew Ramsay stepped out with a well-articulated defense of the stock this morning, reiterating his existing "buy" rating and $115 price target on Ambarella shares. For perspective, that's a roughly 10% premium over Ambarella's current price around $103 per share, and nearly double the $60-per-share price target assigned by Citron in its negative report on Friday.

"While the stock has retreated," Ramsay explained, "our long-term conviction has not. We maintain our belief Ambarella's portfolio of highly differentiated application-specific video encode, compression, and analytics processors positions the company for strong sales and earnings growth as HD and UltraHD video capture and compression become increasingly important across several consumer and enterprise markets."

Ramsay also noted Ambarella is poised to benefit from not only a near-term ramp in sales to existing core markets for video capture devices from the likes of GoPro, but also incremental growth from emerging markets like drones and consumer security cameras this year. In addition, Ramsay says, the industry's move to HEVC compression and 4K resolution at higher frame rates should only serve to further differentiate Ambarella's market-leading video processing solutions from those of its competitors.

Put another way, Canaccord is effectively reminding investors that winners like Ambarella tend to keep on winning -- something with which I wholeheartedly agree. To be fair, that doesn't completely remove the risk of commoditization of Ambarella's products over the long term. But given the near- and medium-term growth opportunities Ambarella is set to enjoy, I think the stock has plenty of upside left before that happens.