Shares of Roku Inc (ROKU) tumbled 5.29% in pre-market trading on Friday, following the release of the company's third-quarter earnings report and fourth-quarter forecast. Despite reporting better-than-expected Q3 results, Roku's outlook for slower revenue growth in the coming quarter has unsettled investors.

The streaming platform provider reported Q3 revenue of $1.211 billion, slightly surpassing analyst expectations of $1.206 billion. Earnings per share came in at $0.16, beating the consensus estimate of $0.09. Roku's platform revenue, which includes advertising and content distribution, grew by an impressive 17% year-over-year, driven by strong performance in video advertising and streaming services distribution.

However, the company's forecast for the fourth quarter has raised concerns among investors. Roku expects Q4 revenue growth to slow to 12%, down from the 14% growth reported in Q3. This deceleration, coupled with projected platform segment growth of only 15% in Q4, seems to have overshadowed the positive aspects of the earnings report. As competition intensifies in the streaming and advertising sectors, Roku's ability to maintain growth and profitability will be closely watched in the coming quarters.