The man who is determined to change the way we watch television has become a billionaire, thanks to the strong performance of the newly listed stock of the company he founded.

Anthony Wood, who incubated streaming-media company Roku Inc. ROKU, -2.55% while working at Netflix Inc. NFLX, -0.05% owns almost 27 million Roku shares, according to regulatory filings. The stock has more than doubled in value since the company reported stronger-than-expected earnings for its fiscal first quarter last Thursday.