Shares of Roku Inc. are up 8.1% in premarket trading after the company announced on Monday afternoon that it was making Walt Disney Co.'s new ESPN+ streaming service available on its devices. Roku also said in a Monday filing that Stephen A. Cohen's Point72 Asset Management had taken a 5.1% stake in the company. Finally, Needham analyst Laura Martin reiterated her bullish stance on Roku shares in a pair of notes to clients following Netflix Inc.'s strong earnings report, one of which was entitled "If you like Netflix, buy Roku."