I use two brokerages and I almost exclusively trade US listed equity options. That's why it's easy to know if I'm getting good liquidity or not; the price doesn't move as much and the spreads are far wider than cash. If I use the one with PFOF, on rare occasions it takes a minute or more for my order to show up on the screens. The other one is very fast with SOR but it doesn't always get a high percentage of the displayed size. When I worked at a shop I got most of the displayed size pretty much all the time because the SOR was way better.
Analogous to the PFOF situation...if a hedge fund sends a limit order to a bank the NBBO may have moved unfavorably by the time it gets sent down to a floor broker. That may be horrible execution but it's not illegal for a floor broker to suck at picking up the phone promptly.
I guess my point is that it doesn't take long to figure out which brokers can improve your committed price, which floors participate aggressively, which electronic crosses break you up, etc, and that knowledge can affect customer fills. But I get what you're saying and you're right that people could monetize it if they had hard quantitative slippage data. That wasn't really what I was describing.
>The reason Nanex is important is that they’ve made bank on proving that risk systems and broker latency don’t matter when enforcing reg nms
I don't understand what you mean by broker latency and Reg NMS...latency between different legs of SOR can affect execution even without a trade-through violation by causing the offer on Exchange B to fade if an order routed to Exchange A crosses the betters there well before the bid destined for Exchange B arrives. I think I'm missing a piece of the puzzle here.
Analogous to the PFOF situation...if a hedge fund sends a limit order to a bank the NBBO may have moved unfavorably by the time it gets sent down to a floor broker. That may be horrible execution but it's not illegal for a floor broker to suck at picking up the phone promptly.
I guess my point is that it doesn't take long to figure out which brokers can improve your committed price, which floors participate aggressively, which electronic crosses break you up, etc, and that knowledge can affect customer fills. But I get what you're saying and you're right that people could monetize it if they had hard quantitative slippage data. That wasn't really what I was describing.
>The reason Nanex is important is that they’ve made bank on proving that risk systems and broker latency don’t matter when enforcing reg nms
I don't understand what you mean by broker latency and Reg NMS...latency between different legs of SOR can affect execution even without a trade-through violation by causing the offer on Exchange B to fade if an order routed to Exchange A crosses the betters there well before the bid destined for Exchange B arrives. I think I'm missing a piece of the puzzle here.