CME Group plans to file a lawsuit against the U.S. Commodity Futures Trading Commission (CFTC) on Thursday, challenging the regulatory body's approval of Kalshi's bitcoin perpetual futures product. Terrence Duffy, the outgoing CEO of CME Group, announced the legal action, expressing concerns over the legitimacy of the CFTC's decision. The lawsuit marks a significant move by CME Group, a major player in the derivatives market, as it questions the regulatory framework surrounding new cryptocurrency products. The outcome of this legal challenge could have implications for the future of bitcoin derivatives trading in the United States.