We analyze a very thorough data base, including all of the bid/ask orders and daily portfolio values of more than 600 on-line amateur traders from February 2007 to June 2009. These traders were taking part in a stock-exchange contest proposed by the French Internet stock-exchange site...

We test here the kahneman (kahneman 2011) results about fund managers: that is, do managers are really skilled or could any chimpanzee do the job? Moreover, the recent stormy period should enlighten us about the interest to invest in mutual funds: do they over perform the market? Do they smooth...