People leave bitcoincash because their block is still not perfect, so they prefer to go back to bitcoincore. And I'm sure bitcoin will reach $ 4000 by the end of this year 
Bitcoin has already touched $4000 this month ,so what will be the next prediction. 
It is good to have two scaling methods and if bitcoin cash have a good scaling solution then it will fly higher,there is nothing wrong in it,only time will tell how good both the scaling solutions are and since bitcoin is a house hold name when it comes to crypto currency,there is no surprise in seeing the price soar so high.Many people who have predictions by the end of this year bitcoin prices can reach $ 10,000, I feel bitcoin will get a correction again, and it will happen in november because the proposal process segwit back running, say I talk nonsense, but I sure can reach $ 7000 at the beginning of the year.