Look at last week's trading in the FTSE 100. The market opened on Monday of last week at around 4400 and closed seven trading days later at around 4400, unchanged on the period. In fact, if you had been away from the market for that period you could have been forgiven for thinking that nothing at all had happened. Admittedly it has been a quiet period, but the index still traded up and down every day. Why is this when nothing fundamental changed on a day-to-day basis to cause the daily fluctuations in the index? Answer: Human sentiment and the different aims of traders.