Group One

Group One holds specialist posts, the floor-era structure that pre-dates the fully electronic options market, on the CBOE and NYSE AMEX. That heritage means standing obligations most purely electronic prop shops never carry: specific classes of listed equity options assigned to it, quoted continuously, with two-sided markets streamed across multiple exchanges at once.

Founded in Chicago in 1989, the firm manages portfolios running to several hundred options issues. Its edge rests on real-time risk systems and software written in-house, and it is registered as a broker-dealer with FINRA. A market maker built on the post system that the exchanges grew out of, rather than one assembled after the screens took over.