Elaborating on U.S. District Judge Gary S. Feinerman’s analysis of Illinois law on the implied covenant of good faith and fair dealing, Judge Steven C. Seeger — who joined the district court in September — denied a motion for reconsideration of Feinerman’s ruling in a case where a futures commission merchant (“basically a broker for derivatives”) sued a group of traders for “failing to pay off the negative balances that had accrued on their futures trading accounts” and their …