But they are not going to leave anyone behind, they are going to establish a separate trading platform that would work accordance to all US laws for providing service to all US residents. The platform would probably be called Binance US.
Changpeng Zhao said it's going to be a fiat-crypto exchange. It'll probably be more like Binance.je than Binance.com, but hopefully I'm wrong and there will still be lots of available markets for US traders.
i don't think they can take that much of the market share if they open up a new "fiat" based bitcoin exchange targeting US only while there is a much bigger and better exchange called Coinbase exists which has most of the market in its control.