Its value nosedived after one of Chinas largest online exchanges, BTCC, announced that it will end bitcoin transactions by September 30. at,that time cryptocurrency briefly fell below the symbolically significant level of $3,000 a coin for the first time in over a month, china has quite a large scale trading going on, so this created a panic and traders were ready to sell bitcoin at lower rates making value of bitcoin to decrease more .but now there is only ban on ICO in china and value of bitcoin is increasing .