I do think that main reason for BTC to go this much up is because of the fork and we still have 8 days until fork happens. I think BTC will go to 6000+ before fork, but that is just my opinion. We will see what will happen.
Yes main reason for current surge in bitcoin price might be fork but there are also lots of other things happening around the world. Banned on chinese trading platform turns out to be good news for bitcoin as most of the chinese traders can't manipulate the price like they used to and many other hype like amazon gonna accept bitcoin in near future have acted positively on bitcoin's price.
$6000+ seems possible before november.