your own bias
bias of others
are we good at it now?
can we predict the stock market?
we made a game, best professional traders, competing against monkeys, we usaly don't win...
the stock price has already been gone up before you got the good news
the price is always right, the information is already in the price
it seems that humans are not so rational, people overreact
maybe then the market is not so rationale
there also emotion and irrationalty in there
this is also true to the stock market