Bitcoin Cash network has completed the mining of first ever 8MB block , Block 479469 was having 40,000 transactions in the block and mined by BitClub. This is kind of testing of first block of the BCH which triggers the sudden price change in the market.
Note that Bitcoin block size was limited to 1MB and also processing was much slower before UASF , though block size of bitcoin would be double to 2MB after segwit activation , it would drastically improve the processing of the blocks and processing fee would be lower which is quite high .
BCH is originated from the Bitcoin and but still in the testing phase of mining and others technical prospects.