Good question about NASDAQ trading. When traders know all the rules about the different market places, they tend to trade listed stocks. Our traders make a big chunk of their money doing opening only trades (which are impossible on the NAZ, since there is no opening...and no single market)and trading off of the imbalances and indications (which you cannot have on a fragmented market), so they simply choose to trade the listed markets. MM's have time to view orders and cancel their bids or offers, etc. (Not a plug, but...you will see an article describing the differences coming soon in either Active Trader or TASC). What I can offer you is only the facts that I know to be true. Our traders must put up $40,000 if they want to trade the NAZ, and when they lose $10,000, we cut them off the NAZ....and we have cut off everyone except for a handful of arbitrage traders and ex Market Makers. It's not that I am against the NAZ, it is that I am FOR the traders making money. In all seriousness, there is a lot to all of this, too much to bore you with on the board. I hope this helps.