Realizing that computers would lead to automated exchanges and mathematical securities pricing, he founded Hull Trading Company in 1985.
Henry M. Paulson, then chairman and chief executive officer of Goldman Sachs, said Hull Trading Group is "the world's largest electronic options market maker, very active outside the U.S. We just looked at this as something that's going to position us well.
The firm employed complex mathematical models to analyze short-term options and equity pricing discrepancies while hedging against overall risk exposure.
A proprietary and large scale reliable distributed system architecture was developed by company programmers, providing automatic real-time pricing, risk management, market making and interconnection with automated options, futures and stock exchanges as they became available.
Hull's massively scalable software technology was deployed to cover both domestic and international markets as electronic, on-line exchanges became available, while innovative hand-held computer technology was employed at exchanges still requiring execution by floor traders.