Can someone explain to me why china is trying to ban bitcoin.?
Try to do some more research about this latest news. China is not banning bitcoin, nor does the country ban altcoins for that matter. China is banning ICOs. Perhaps some regulations will take place about ICOs. Crypto exchanges are also being treated with very strict measures, even closing some.
Yes, some of the exchanges are perpetuating money laundering and the government wants to get strict on the ICO's and if possible the exchanges with whom these illegal moneys are converted into the Chinese yuan and vice versa.