Trading bitcoin is a negative-sum game because of the bank and trading fees.  Exchanges do not create any money or bitcoin, but they consume some of both when coins and dollars move through them or inside them.

Suppose that, since 2009, all the traders, current and past, put a total of X bitcoins and Y dollars into the exchanges (both net, deposits minus withdrawals).  Because of the fees, all those people together now have less than X bitcoins and less than Y dollars left in their exchange accounts.  So, as a group, they lost some bitcoins and lost some money.  No matter how the deposits, withdrawals, and balances have been divided among those traders, and how you measure the gains and losses, every gain that a trader made is more than offset by the losses of other traders.