What happened

Shares of Roku (NASDAQ:ROKU) soared 46.7% in January, according to data from S&P Global Market Intelligence, after the streaming-media platform leader preannounced select fourth-quarter 2018 results.

It helped that the broader market rebounded nicely last month after a difficult December. But Roku stock also popped more than 25% on Jan. 7 alone -- the same day the company revealed that its number of active accounts climbed 40% year over year to 27 million, while its quarterly streaming hours skyrocketed 68% to 7.3 billion. 

Display showing ROKU's streaming media platform

IMAGE SOURCE: ROKU.

So what

"Strong active account growth and accelerating streaming hours point to consumers' growing enthusiasm for streaming, making Roku America's largest and fastest-growing TV streaming distribution platform," said Roku CEO Anthony Wood.

Roku's exceptional 68% increase in streaming hours marked a 5-percentage-point sequential acceleration from the third quarter and brought the metric's growth for the full year 2018 to 61%. The move further indicates a continued shift for Roku away from its previous core streaming player sales and toward its higher-margin, higher-growth platform segment -- a trend that recently spurred one analyst to label Roku her "Top Pick for 2019."

Check out the latest Roku earnings call transcript. 

Now what

Roku is scheduled to release both its full fourth-quarter 2018 results and 2019 outlook on Feb. 21. But considering its encouraging preview of two key metrics ahead of that report, and with shares entering 2019 having fallen more than 60% from their October highs, it was no surprise to see the stock rebound in a big way last month.