Arthur Hayes and his BitMEX co-founders must each pay a $10 million fine, but contesting the case against them might have clarified which financial regulatory agency should have primary oversight of cryptocurrencies; a tough weekend for cryptos.Read MoreFeedzyArthur Hayes and his BitMEX co-founders must each pay a $10 million fine, but contesting the case against them might have clarified which financial regulatory agency should have primary oversight of cryptocurrencies; a tough weekend for cryptos.