Trading and Exchanges Chapter 5: Hybrid Markets and Trading Sessions (Part 2)
In Part 1 we covered trading sessions and the main execution systems: quote-driven dealer markets and order-driven markets. Now let’s get into brokered markets, hybrid structures, crossing networks, and the information plumbing that holds everything together.
Brokered Markets: When Nobody Wants to Go First
Brokered markets exist because some trades are just too big or too unusual for regular dealers and order books. If you want to sell a $500 million block of stock, you can’t just drop a market order on an exchange. You’d crash the price before you finish filling it.
In brokered markets, brokers actively search for willing counterparts. They call around, feel out who might be interested, and try to match buyers with sellers. Two types of liquidity suppliers show up here. Concealed traders know they want to trade but refuse to show their hand publicly, because that information alone can move prices against them. Latent traders don’t even know they want to trade until a broker calls with an attractive opportunity.
Brokered markets are everywhere. Real estate. Entire businesses. In securities, the big block trading desks are basically brokered markets. Dealers won’t hold positions in items that are too large or trade too rarely, and nobody wants to post a standing order for hundreds of millions of dollars where everyone can see it.
Hybrid Markets: The Real World Is Messy
Almost no major exchange is purely one type. Most real exchanges are hybrid markets that mix elements of all three structures.
The New York Stock Exchange is mostly order-driven, but it requires specialist dealers to step in and provide liquidity when nobody else will. So it has a quote-driven element baked right in. The Nasdaq Stock Market is mostly quote-driven, but it requires dealers to display public limit orders and sometimes execute them. So it has an order-driven element. And when brokers arrange large block trades in either market, both function partly as brokered markets too.
Textbooks love clean categories, but reality is messy. If someone tells you “the NYSE is an auction market” or “Nasdaq is a dealer market,” that’s an oversimplification. Both are hybrids. The question is always which element dominates.
Crossing Networks: Price Takers, Not Price Makers
One special type of order-driven market that Harris describes is the crossing network. These are systems that match buy and sell orders at prices determined somewhere else, usually the midpoint of the current bid-ask spread on a primary exchange.
Crossing networks don’t do price discovery. They just take the price from another market and match orders at that price. Great for institutional traders who want to trade large blocks without paying the spread and without revealing their intentions.
The downside? You can only trade when there happens to be a matching order on the other side. You might submit an order and wait hours with nothing happening. No guarantee of execution. But when it works, you save a lot on transaction costs.
Transparency: Who Sees What
Markets vary hugely in how much information they share. Harris breaks transparency into two kinds. Ex ante transparency (pre-trade) means you can see orders and quotes before trades happen. Ex post transparency (post-trade) means you can see trades after they happen.
U.S. stock and options markets are generally very transparent. U.S. futures markets are ex post transparent but not very ex ante transparent, because in open-outcry pits, quotes don’t last long enough to report. Corporate and municipal bond markets? Pretty opaque. You often have no idea what other people are paying.
Here’s the interesting tension. Traders want to see what everyone else is doing, but they don’t want anyone to see what they’re doing. The less informed you are, the more you want transparency. The big information holders oppose it because they don’t want to give up their edge.
Harris notes that investment banks make more money trading bonds than stocks. The explanation? Probably transparency. Stock markets show you the quotes, so customers negotiate better prices. Bond markets are opaque, so dealers keep fatter margins.
Order Routing and the Plumbing
The rest of the chapter covers order routing: the mechanics of getting orders from point A to point B. Used to be runners carrying paper tickets across a floor. Then telephones. Now mostly electronic.
Electronic routing is faster, cheaper, and more accurate. But it handles only standardized orders. For anything unusual, you pick up the phone. Floor traders have an advantage because they see market developments before off-floor traders get the data. The best data systems in Harris’s era had a 3-second delay. Order routing added another 5 seconds. That’s an edge for the person standing on the floor.
Harris also covers order books, where exchanges store unfilled limit orders. Open book markets let everyone see the orders. Closed book markets keep them hidden. Many traders want to see the book but don’t want their own orders in it. Some exchanges, like Euronext, let traders submit undisclosed limit orders as a compromise.
The Big Takeaway
Market structure is not one thing. It’s a combination of session type, execution system, transparency level, and the technology that moves information around. Every real exchange is a unique blend.
The structure determines who has power. Who sees information first, who can act fastest, who gets the best prices. If you don’t understand the structure of the market you’re trading in, you’re at a disadvantage. Someone else knows the rules better, and they’re using that to take your money.
That’s the lesson Harris keeps hammering, and Chapter 5 is where you really start to see why it matters.
Previous: Chapter 5: Market Structures (Part 1)