Although Bitcoin started the past week with an impressive four-day rally that took the price all the way from $6,575 to 7,827, it finally succumbed to gravity towards the end of the week after news came out about an attack on South Korean crypto exchange Upbit's hot wallets, the mysterious disappearance of the CEO of Chinese crypto exchange IDAX, and the arrest of Ethereum researcher Virgil Griffith in Los Angeles after he gave a talk at a North Korean crypto conference.