IEX Group has secured a legal victory against Citadel Securities, paving the way for the launch of its new options exchange. The U.S. Court of Appeals for the Eleventh Circuit upheld the SEC's approval of IEX Options, rejecting Citadel's challenge. This decision allows IEX to proceed with its planned launch on October 2, 2026. The legal dispute centered around IEX's Options Risk Parameter, a 350-microsecond delay designed to protect liquidity providers from latency arbitrage. Citadel argued that this mechanism was anticompetitive, but the court disagreed. IEX's options exchange aims to prioritize customer orders and use a pro-rata allocation model, potentially benefiting retail investors.