Amid sharp, mostly downward volatility in crypto markets, BlockFills has halted withdrawals and restricted trading on its platform, a person familiar with the matter told CoinDesk. Clients were informed of the decision by internal email, according to TheMinerMag. Based in Chicago and backed in part by market-making giant Susquehanna Investment Group, BlockFills saw $60 billion in trading volume last year, according to the Financial Times. "In light of recent market and financial conditions, and to furt ...