We're just a handful of days into 2019, and some stocks are already off to the races. There are hundreds of stocks that are already posting gains of 20% or better this young year, and it's not just a matter of momentum lifting last year's hot stocks even higher.

A lot of this year's big winners had a rough 2018. GameStop (NYSE:GME)Roku (NASDAQ:ROKU), and Camping World (NYSE:CWH) plummeted 24%, 41%, and a brutal 74%, respectively, last year. They're all riding high through the first five trading days of 2019. Let's see what's driving the early turnarounds in the three one out-of-favor stocks.

Camping World storefront in Bowling Green.

Image source: Camping World.

GameStop -- Up 25%

Check out the latest GameStop earnings call transcript.

The small-box retailer of video games is battling the digital delivery revolution. Diehard gamers still love their consoles, but expansion packs and console-fueled online marketplaces are eating away at the velocity of purchases of physical game media. GameStop's model has taken a hit, especially since it scores its highest margins in reselling used games and gear. 

The good news is that GameStop isn't dying anytime soon. The stock took a hit in late November after the chain slashed its profit forecast, but it remains very profitable with a strong balance sheet. 

The bounce this year has been largely speculative. The Wall Street Journal reported last week that a pair of major private equity firms are bidding on GameStop, expecting a deal to be announced by next month. GameStop has been buyout fodder for months, and taking it private seems inevitable at some point. The real danger here is that the stock can appreciate to the point that an acquisition may no longer be attractive to a potential buyer, but we'll cross that level's end boss when we get there. 

Roku -- Up 33%

Check out the latest Roku earnings call transcript.

The pioneer of streaming media was a rock star when it went public in 2017, but last year was rough. Roku was able to grow its audience and its platform's stickiness, but valuation concerns and fears that tech giants were flooding the market with subsidized gadgetry weighed on the stock's performance. 

The bulls have come back in 2018, fueled by Roku's announcement last week that it now has more than 27 million active accounts on its platform. A record 3.2 million net additions during the holiday quarter finds its user base soaring 40% over the past year. A record 7.3 billion hours of content was streamed on Roku devices or smart TVs running Roku's operating system, a 68% surge since the prior year's fourth quarter. It's refreshing to see usage outpace ownership growth, a strong indicator that average revenue per user will continue moving higher. 

Camping World -- Up 31%

Check out the latest Camping World earnings call transcript.

One of last year's biggest losers was Camping World. The top dog in the highly fragmented RV superstore market tumbled through 2018 as margins were squeezed. A year that began with lower-margin towables gaining market share at the expense of pricier RVs ended with even the towables falling out of favor.

Camping World has now fallen short of Wall Street's profit targets for three consecutive quarters, and that's never a good look. The stock started to rebound after announcing a management shakeup last week, but after surrendering nearly three-quarters of its value last year, investors will want to make sure that this is a sustainable bounce. Camping World expects to continue growing by acquiring independent outlets, but it will need RV trends in general to firm up if it wants to continue the turnaround.