… but insider information is.
Recent research (pdf) found that averagely informed traders perform worse than the non informed and only traders with high levels of information (insiders) are able to beat the market.
The conclusion: The results suggest that only those traders with near perfect information can beat the market. Of course, attaining perfect information in real-world markets is equivalent to attaining insider information that is generally unavailable to the marketplace.
In the immortal words of Gordon Gekko: You stop sending me information, and you start getting me some.
Related:
The illusion of knowledge
The value of publicly available information is zero
Information Overload