Media-aware stock performance has been well recognized in recent studies. Previous research, however, focused on the content influence of the media, ignoring the manner in which the media is delivered. Based on the trust theory, this study argues that the media platforms, as media distribution vehicles and trust endorsement for news, are themselves influential on the stock market. This paper collected news data from seven Chinese mainstream media platforms and classified them into official, professional, and mass media platforms to investigate the impact of different platforms. The authors find that high official and professional media coverage predict increased abnormal returns, while high mass media coverage predicts the opposite. In addition, this paper systematically explores the mechanism of media platforms on stock performance from the perspectives of platform content, audience, and publication timeliness. The findings include that investors' attention to media platforms has a moderating effect on the stock performance, and such an effect is more salient in bear markets.