People are buy more Bitcoin so that they can gain more profit from the free B2X they are going to receive after the fork.
They will either sell the BTC for fiat or buy Altcoins for BTC after the fork. So the resulting change will be vice versa after the fork.
It will really affect the value and fluctuation of each and every coins regarding this coming Fork and I think Bitcoin is the more affected one than every Altcoins out there, we can see it from the bitcoin price and because of this hard fork money is getting into bitcoin because many are expecting to get free coins from the upcoming Hard Fork.
Exactly this. I hate free coins!