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i think our bitcoin is not loss if we save in offline wallet. but i think we can still save our bitcoin in exchange but not in big amount so we still can doing trading. if there is any split like many rumor said, then we can have new coins and if the price is high then we can have free money for selling the coins.
Yes it won't be lose if you'll store your bitcoins on your offline wallet. It's advisable to store your bitcoins not on exchange but to an offline wallet where you have full control of your private keys.
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I am sure that you wont loose you coins but you might loose the benefits of the split as usually you are supposed to get coin on a equal ratio of 1:1 if there is a split and if you save your coins in exchanges then you wont get those but that does not mean that your coins will vanish because the coin with the biggest followers will be the leader and that will be the coin you will be getting if you store your coins in an exchange.
Oh yes, thanks for correcting me mate. Yes you won't lose your bitcoin but once the split happens and you don't have control on your keys we can't tell what's possible to happen to the exchange. If they will decide to support the chain that they have but if you stored your bitcoins in an offline wallet, you can have two chains.