There are local wallet like the free copay wallet you can find on your phone's app store. As long as you use local wallet which generate and hold the private key you are save. I sold bitcoin yesterday and went to steem and will go back when fork is over to avoid dealing this this mess and I don't know if you actually gain when it splits. Like a stock split no new value is created. May be the new coin will have better acceptance and gain value but I don't know for sure and isn't putting any money on it.