In a criminal complaint, Thakkar, 41, of Naperville, is accused of developing a software program that helped an unnamed commodities trader engage in “spoofing,” placing thousands of bids or offers on the E-mini S&P, a market on the Chicago Mercantile Exchange, with the intent of canceling the trades before they were executed, but after bids were placed on the other side of the market. Thakkar was not immediately available for comment.