The view of futures market is primarily a mechanisim for the
short and long hedgers to offset their respective risks.
under this the expected spot price is only future price and it
will not have any profit or loss.
The condition under which it will depend upon is whether future
buyer are being compensated for taking price risk that the future
seller are avoiding.
It is always assumed that the future transactions are dirven by
natural short hedgers risk transcating with the long hedgers
expected future price is equal to expected spot price.