My one suggestion is that you might want to re-consider your categorization of markets as intermediated or non-intermediated. Simply having a trading floor does not mean that a market is intermediated, and being “all-electronic” does not mean that a market is non-intermediated. For example, at NYSE, for the vast majority of orders, buyer and seller meet directly and electronically, without a dealer participating. If you’re using a floor broker as agent for your order, I would consider that broker an agent, not an intermediary. And on a market such as Nasdaq, you might buy or sell shares from a dealer (an intermediary), or an electronic communications network, or some combination of the two. The lines are not so black-and-white anymore.

If you or your readers would like to see further discussion about our Hybrid Market, our blog is at http://hybridtalk.nyse.com

Thank you! — Ray Pellecchia