whether the cause of this is happening, is it something to do with the decision of the south korea government?
I think this is clearly related to the South Korean government's decision, especially the South Korean financial authorities, they have deployed tax agents and police to conduct raids on six local banks, and the Cryptocurrency Exchange (Coinone and Bithumb). Both are the second largest virtual currency operator in South Korea.
Read more at
https://www.bloomberg.com/news/videos/2018-01-11/bitcoin-drops-as-south-korea-constructs-trading-ban-videoBased on Bloomberg data, Omnitel, which owns bitcoin remittance business, fell 30%, Vidente shares plunged 29.96%, Digital Optics slipped 14.42%, and KPM Tech fell 4.90% in today's trading.