I have been wondering the same thing about needing BTC or ETH for most of the exchanges. It reminds me of the PetroDollar. It looks just like using BTC / ETH as a 'reserve currency' perspective. So, YES, exchanges working based on BTC/ETH , and controlling them controls the whole market.
At this point, I think it is all owned by the banks. This is a 60% crash. Maybe the space was in a bubble but this is like a monkey shit fight at the zoo. Hopefully this is the banks getting ready for a $600,000,000,000 pump and dump.
Also, the futures started at midnight Sunday ( I think I went straight down).
It's a huge crash. It appears slow and consistently downward to me, not an immediate collapse. Almost looks as incredible as the rise!