O'Connor & Associates was a Chicago-based options trading firm, with particular emphasis on financial derivatives. The firm was acquired by Swiss Bank Corporation (later merged with Union Bank of Switzerland to form UBS). O'Connor was headquartered in Chicago and occupied the former offices of the Chicago Board of Trade. At the time of its acquisition by Swiss Bank Corporation, O'Connor had over 600 employees worldwide, 230 of which were based in Chicago. The remaining 400 employees were involved with O'Connor's Swiss Bank joint venture, which was formed in 1989.'. History O'Connor was founded in 1977 by mathematician Michael Greenbaum and was named for Edmund (Ed) and Williams (Bill) O'Connor. The O'Connor brothers had made a fortune trading grain on the Chicago Board of Trade and founded First Options, a clearing house. The O'Connors provided Greenbaum, who had run risk management for First Options, with the capital to start his own firm. SBC had established a strategic relationship with O'Connor, which was the largest market maker in the financial options exchanges in the U.S., beginning in 1988. O'Connor had been looking to partner with a larger financial institution. O'Connor entered into a currency joint venture with SBC, in 1989, that proved to be the first step towards a sale of O'Connor to SBC. Following a 1992 merger, O'Connor was combined with SBC's money market, capital market, and currency market activities to form a globally integrated capital markets and treasury operation. A number of O'Connor executives were brought into key positions within Swiss Bank. References UBS Former investment banks of the United States American companies established in 1977 Banks established in 1977 American companies disestablished in 1992 Banks disestablished in 1992 1977 establishments in Illinois 1992 disestablishments in Illinois