the founding document of the new york stock exchange was an agreement to collude and price fix:
"We the Subscribers, Brokers for the Purchase and Sale of the Public Stock, do hereby solemnly promise and pledge ourselves to each other, that we will not buy or sell from this day for any person whatsoever, any kind of Public Stock, at a less rate than one quarter percent Commission on the Specie value and that we will give preference to each other in our Negotiations. In Testimony whereof we have set our hands this 17th day of May at New York, 1792."
https://en.wikipedia.org/wiki/Buttonwood_Agreement
