Security prices reflect all information, both public and
non-public
It is not possible to beat the market
The implication on portfolio management is that :
Active portfolio management is not worthwhile because the
effort and resources spent on trying to beat the market will be
futile. Further, the expense ratio of active funds is high, which
means that the net returns earned by active funds will be lower
than the market returns
Passive portfolio management (index funds) are a better option
because they have lower expense ratios, and the resources used in
active management can be deployed elsewhere