What: Shares of Ambarella (NASDAQ:AMBA) and GoPro (NASDAQ:GPRO) each fell as much as 10% early Monday, then partially recovered to close down a little more than 5%, after GoPro suffered yet another negative analyst note. 

So what: Similar to last Friday's plunge, Ambarella's move came without any new company-specific events, but rather appears to be a sympathetic decline on GoPro's "bad" news. Ambarella has previously relied on GoPro for as much as 30% of its overall revenue, and last quarter blamed disappointing guidance on headwinds in the wearable camera segment primarily associated with the action camera maker.

Meanwhile, after meeting with GoPro's director of investor relations, Peter Salkowski, at CES 2016 last week, Morgan Stanley analyst James Faucette reiterated his "Underweight"rating on GoPro, which he initiated four weeks ago with a $12-per-share price target.

"Salkowski echoed our own channel findings that holiday sales of lower-priced drones did not fare as well as retailers had hoped," Faucette explained, "but he expressed optimism that GoPro's brand would help demand, whatever its pricing might be."

For perspective, GoPro is still planning to launch its own quadcopter the first half of this year but didn't offer investors a look at what it previously described as its "differentiated" solution.

Faucette also said Salkowski "acknowledged that the company must do substantially more on the software side to improve usability, consistent with our views from the outset."

Now what: On one hand, the pessimism surrounding these two companies is palpable, so it's hardly surprising investors were willing to take yet another step back on any hint of negative news.

On the other hand, at this point the gravity and speed of the declines of Ambarella and GoPro are starting to border the absurd -- especially considering Faucette's note was, more than anything, aimed at justifying a bearish call he made almost a month ago. As a result, with shares of Ambarella and GoPro now trading at just 16.1 and 12.7 times trailing 12-month earnings, respectively, I think long-term investors willing to take advantage of these prices will be handsomely rewarded.