In its options-trading heyday of the 1980s and ’90s, lots of of members traded choices in world currencies, Dell Pc, and different standard choices contracts. The market has served as an incubator for Philadelphia buying and selling and know-how companies, resembling Susquehanna Worldwide Group, the multibillion-dollar buying and selling and funding firm primarily based in Bala Cynwyd, which traces its roots to the Philadelphia exchange buying and selling ground.