Yes,i got warning from twitter.
Civic CEO Vinny Lingham shared the following advice to all Bitcoin users:
I recommend to people in Bitcoin to have two pots. One is your long term BTC holdings, cold storage. Never sell those. Trade the other pot.
Prepare for hard fork:
Although its hard to tell exactly which Bitcoin services will support Core, BU or both, users can expect their coins to be available on both chains.
Keeping your bits on your own personal wallet, in which you control the private keys, is advised, as this would ensure that your coins are credited on both blockchains.
One could then access the BU coins via the Bitcoin Unlimited client and the original chains coins via any wallet that supports Bitcoin Core. Keeping coins on an exchange is not recommended.
Coins on an exchange are not yours. Thats true regardless of any possibility of a fork, Antonopoulos notes.
However, if you do store your coins on an exchange, the most likely event would be the exchange will credit your coins on both chains, though its a decision that will be left entirely up to the exchange operators.
To play it safe, keeping your bits on your wallet and keeping your funds in cold storage/offline is highly recommended.