What: Shares of GoPro (NASDAQ:GPRO) fell as much as 10.3% early Friday, then settled to trade down around 7% as of 1:45 p.m. on no new company-specific news.

So what: Rather, on the heels of GoPro's painful third-quarter report late last month -- in which the company badly fell short of its own expectations and issued disappointing holiday-quarter guidance -- it appears the market's sentiment toward shares of the action camera maker has only continued to sour. According to MarketWatch, short interest tracker Sungard Astec Analytics named GoPro the No. 1 U.S. "hot stock" for short sellers for the second straight week on Wednesday, noting demand to borrow shares is exceeding supply.

Now what: Keep in mind while this plunge is no doubt painful to watch, nothing has really changed with regard to GoPro's underlying business.

That also means GoPro has plenty of work to do to revitalize demand for its core camera products going forward. But management is taking action to do so including ramping advertising (in retrospect, GoPro believes it under-funded marketing in the second and third quarters), and correctly pricing its now-$299 HERO4 Session camera in time for the holidays. In addition, GoPro investors can likely look forward to a refreshed camera line up to stoke demand in the coming year, as well as the launch of its new quadcopter capture solution in the first half of 2016.

As it stands, with shares now trading below GoPro's $24 IPO price for the first time, I think investors would be wise to put the stock on their watch list.

Steve Symington has no position in any stocks mentioned. The Motley Fool owns shares of and recommends GoPro. 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 Motley Fool has a disclosure policy.