This is a rather complicated piece but the abstract does a very good job of summarising the papers content.
We present a simple model in which rational but uninformed traders occasionally chase noise as if it were information, thereby amplifying sentiment shocks and moving prices away from fundamental values
The notion of chasing noise as if it were information is a very powerful statement within the context of how traders behave. Note also that they do make the assumption that investors are rational, a point which I could disagree on since a rational investor would not chase noise as if it were information. However, the basic thrust of the article is not really undermined by this since the modern trading environment is a very noisy place and humans are prone to distraction.