In Round One of litigation about arbitration between INTL FCStone Financial and a bunch of customers who lost lots of money trading natural gas futures in 2018, a federal judge in Chicago ordered the defendants to arbitrate their claims through the National Futures Association. The arbitration started here, as required by Section 4 of the Federal Arbitration Act (“The hearing and proceedings, under such agreement, shall be within the district in which the petition for an order directing such arbitration is filed …