I did not know that. I remember when the Grasso pay scandal was happening the justification for paying him was that he had made the stock exchange members a lot of money. I know that you had to buy interests in the stock exchange, but i didn't realize that you didn't get a piece of any profits the exchange earned. I guess that money went into a fund like at a country club.
When the ISE went IPO, the firm i worked at owned a few bins and they made a ton (like 20MM on a 2MM investment). But i don't think they received any dividend checks prior to that - but all that would have been above my pay grade at the time anyway.