To be a Roku shareholder, you need to believe that the continued shift toward streaming and digital advertising will offset risks from competition and ad market volatility. The recent hire of Lisa Holme as head of content is not expected to materially alter Roku's biggest near-term catalysts, chiefly, increasing ad monetization and user growth, or address the immediate risk from larger competitors moving aggressively into smart TV operating systems, which could challenge Roku's market share and revenue growth.