A man walks past an electric board showing exchange rates of various cryptocurrencies including Bitcoin (top L) at a cryptocurrencies exchange in Seoul

A man walks past an electric board showing exchange rates of various cryptocurrencies including Bitcoin (top L) at a cryptocurrencies exchange in Seoul

A man walks past a board showing exchange rates of various crypto-currencies in Seoul. Photo: Reuters/Kim Hong-Ji

December 20, 2017 4:07 PM (UTC+8)