Do you remember the previous fork this year when bitcoin split into two and that is BTC and BCH. Those who have a btc on the exchanges have received an equivalent amount of BCH on their balance after the fork. The same thing will happen to the fork , after the fork those who have balance on the exchanges will also receive the same amount of coins in the form of BTC Gold.
If that's the case then I guess time to party as the fork is near and we are ready to get the free BTC gold in our wallets.
I prefer to keep my BTC on Bittrex as I did the last time when BTC was forked and I got BCH in my bittrex wallet.
The advantage of keeping BTC on exchanges is that when we get free BCH or BTG its quite easy to trade it quickly on the exchange.