Screen Shot 2015 10 29 at 7.08.51 AMGoogle
GoPro shares crashed to an all-time low on Wednesday. 
Shares in the digital-camera maker were down by as much as 18% in pre-market trading on Thursday, following yesterday's plunge after the company reported a miss on earnings and offered weak guidance.
The important numbers:
Adjusted earnings per share in Q3 came in at $0.25, while analysts had estimated $0.29, according to Bloomberg.
Revenues totaled $400.3 million, up 43% year on year, but missing the estimate for $433.6 million.
Guidance was ugly. During the earnings call, management forecast Q4 earnings of $0.35-$0.45, which is half the $0.82 expected by analysts surveyed by Bloomberg. Citing low visibility, management estimated Q4 revenue of $500 million to $550 million, which isn't close to the $688 million expected by analysts.
GoPro announced that its board has authorized a $300 million stock-buyback program, starting in the fourth quarter.
GoPro shares are down about 53% year to date. 
CEO Nicholas Woodman said in the earnings statement, "I am proud of our year-to-date accomplishments in which we posted strong financial results and expanded our portfolio of products, however our business in the third quarter was clearly more difficult than anticipated."

Screen Shot 2015 10 28 at 4.13.49 PMGoogle FinanceGoPro shares year to date.
The company launched a couple of products in the past quarter, including the Hero 4 Session, its smallest offering yet. Morgan Stanley analysts thought it was a flop. GoPro reduced the price by $100 to $299 after what they called "disappointing demand."
Other analysts sounded the alarm on competition from other manufacturers and were concerned about whether the company could significantly grow its user base outside the core group of enthusiasts. In the earnings statement, the company said its products made up five of the top 10 products in the digital-camera and -camcorder category in the US.
Then there was the brutal Barron's magazine article in September, which forecast that GoPro shares could plunge to $25, right about where shares dropped to in after-hours trading on Wednesday.
Again, the concern for Barron's Alexander Eule was competition.
In a note Wednesday, Pacific Crest's Brad Erickson (who rates the stock "Sector Weight) wrote, "Outside of the headline-worthy disappointing Q4 revenue guidance, the company’s negative commentary regarding Hero 4 Session demand reinforced our views from our checks over the past few months that the action camera market in the United States appears to be quickly saturating."