Here is the reason for the fall in Bitcoin and Etherium.
http://www.zerohedge.com/news/2017-09-04/ethereum-bitcoin-crash-after-china-declares-initial-coin-offerings-illegal
"Ethereum and bitcoin are crashing this morning, after China confirmed its recent threat of an ICO crackdown (reported here last Monday) when the central bank said on Monday that initial coin offerings are illegal and disrupt financial markets, according to statement on Chinas central bank website. The PBOC also asked all related fundraising activity to be halted immediately, issuing the strongest regulatory challenge so far to the controversial if surging market for digital token sales."