While the market has performed nicely over the past year, not all stocks have taken part in the positive Wall Street sentiment. For Fitbit (NYSE:FIT), Under Armour (NYSE:UAA)(NYSE:UA), and GoPro (NASDAQ:GPRO), they not only didn't participate in that growth; they saw their value decline around 50% or more. Here's what sent those stocks down, and a look at what their future might hold now.  

Fitbit can't catch a break 

Fitbit shares are down a full 62% over the past year. The market has punished Fitbit for slowing sales growth and an overall feeling of a passing wearable-fitness trend. Fitbit's latest share-price drop came after it released preliminary Q4 results on Jan. 30 that showed sales would be well below previous guidance, and that 2016 full-year revenue growth would be about 17%, compared with the 25% previously forecast. The company said it now plans to reduce costs, partially through reducing its workforce by 6%. 

A man eating a healthy meal, with a focus on the Fitbit activity tracker on his wrist.

Image source: Fitbit.

Fitbit certainly still has a few bright spots. For one thing, Fitbit still has a large -- and growing -- active user base, which, as of the recent earnings pre-release, was at an all-time high of 23.2 million. The company has also announced a slew of partnerships and programs in the healthcare space that management thinks could be a big part of Fitbit's future. Otherwise, even if Fitbit's sales and earnings don't pick up again soon on its healthcare and smartwatch strategy, the company still has a solid balance sheet with no debt and a healthy cash position that could be ripe for an acquisition. 

Under Armour gets a lot more affordable

Under Armour's "A" shares have fallen around 46% over the past year, after the stock took a hit following Q3 earnings in October, and again with Q4 and full-year results in February. Under Armour had once been a market darling, posting 20% or more sales growth year over year for 26 quarters in a row, and the market had allowed it a price-to-earnings multiple of as much as 100. The recent Q4 results marked the first time in more than six years that the company reported below 20% year-over-year sales growth, at just 12%, and management guided for about that same rate of growth for the full year 2017. 

The company also faces the challenge of proving its earnings ability. The market reacted negatively to CEO Kevin Plank's comments following Q3 earnings that the company would no longer meet a previously set 2018 earnings goal because the company was investing more heavily in future growth. That story was harder to swallow when Q4 sales also took a deep dive, meaning that the company needs to prove it can pick up sales again and then still get money back to the bottom line. 

The market has now dropped Under Armour's valuation substantially, but there could actually be a buying opportunity for long-term investors who still believe in the brand's ability to regenerate growth. International sales, which make up only about 15% of Under Armour's total sales now, grew 63% in 2016 year over year, and the brand plans to continue pushing overseas. The same is true of footwear, which makes up about a fifth of total sales but has grown 50% in 2016. 

GoPro misses its shot

GoPro stock is down about 25% over the past one year, but it's fallen 50% from Jan. 1, 2016, to now, after the company took a major cut during January 2016 following an unexpectedly rough holiday 2015 quarter. The trouble seems to have mostly stuck with the stock through the next year, and as of the recently announced 2016 holiday-containing quarter, the company continued to struggle to meet even its lowered expectations. For the fourth quarter, reported Feb. 2, GoPro's sales rose 24% year over year, but the numbers fell substantially short of analyst expectations, and full-year sales were down 27%. The company also reported a GAAP loss per share of $3.01 for the year, compared with a positive earnings per share of $0.25 in 2015.

The Karma drone, with four helicopter blades and a GoPro camera in the middle for aerial shots.

The GoPro Karma Drone. Image source: GoPro.

The Q4 earnings press release noted that during the quarter, the HERO5 Black and HERO Session GoPro models were the No. 1 and No. 2 best-selling digital image cameras, on a unit basis, in the United States. In addition, GoPro's long anticipated Karma drone, which caused embarrassment when it was recalled shortly after being launched last November over issues with the camera casing and battery latch, is now on sale again. Other bets the company is making include its Quik mobile app, which the company said saw December monthly active users and monthly exports triple year over year.

Is GoPro a bargain now? The company still faces some serious questions over its long-term growth viability, both because of cheaper competitors flooding the market and because of company missteps that cast some doubt on management's ability to capitalize on its market-leading name. Still, like Fitbit and Under Armour, the company could have some avenues to growth, both through international expansion and investments in future product categories that could turn its fortunes around. Keep these stocks on your watch list as potential cheap plays if it looks as if they're about to break out of their tailspin.