【Abstract】This paper examines the effect of news topic concentration (TCR) on Chinese stocks. Our empirical findings reveal a U-shaped relationship between TCR and market reaction, which is mediated by investor attention. Information ambiguity complements attention's role at low TCR. Moreover, TCR has a greater effect on stock prices when firms have lower institutional ownership, higher information uncertainty, and when the news originates from state-controlled media. Additionally, we observe that the U-shaped patterns differ across dominant meta-themes. Our results highlight the importance of the structure of the information present in its integration into asset prices and emphasize the role of journalists as key information intermediaries.