I'm willing to bet that this is happening because people are trying to get coins before the fork happens on November 16th.
The biggest factor for me is that the miners are pissed off that both SegWit chains are meant to cannibalize the core tenets of Bitcoin with the goal of privatizing fees. This post explains it way better than I ever could:
https://theflippening.github.io/open-letter-to-bitcoin-miner...
I've moved 92% of my BTC -> BCH, and I've grabbed my popcorn. It's going to be an interesting month.